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prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
2994
091acec720664c15b3c2da44698978c6
[ "其它" ]
1
single_choice
Mariam had $$$4y$$. After buying some cloth at $$$7$$ per metre, she had $$$y$$ left. How many metres of cloth did she buy?
[ [ { "aoVal": "A", "content": "$$\\frac{3y}{7}$$ " } ], [ { "aoVal": "B", "content": "$$\\frac{5y}{7}$$ " } ], [ { "aoVal": "C", "content": "$21y$ " } ], [ { "aoVal": "D", "content": "$$35y$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions" ]
[ "Amount of money she spent to buy the cloth $$\\rightarrow$$$$$4y-$$$$$y$$ $$=$$$$$3y$$, Length of cloth she bought $$\\rightarrow$$$$$3y\\div $$$$$7/\\text{m}$$ $$= \\frac{3y}{7}\\text{m}$$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
2995
0f931b5bb90746c8bcbbe42900113c52
[ "其它" ]
1
single_choice
The mid points of the four sides of a rectangle are $(−3,0)$, $(2,0)$, $(5,4)$, and $(0, 4)$. What is the area of the rectangle?
[ [ { "aoVal": "A", "content": "$$20$$ " } ], [ { "aoVal": "B", "content": "$$25$$ " } ], [ { "aoVal": "C", "content": "$$40$$ " } ], [ { "aoVal": "D", "content": "$$50$$ " } ], [ { "aoVal": "E", "content": "$$80$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "NA " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3004
3837cbbd0ce24bc3a9672bdce2914a8b
[]
1
single_choice
Pick two consecutive positive integers whose sum is less than $$100$$. Square both of those integers and then find the difference of the square numbers. Which of the following could be the difference? ($2007$ AMC $8$ Problem, Question \#$19$)
[ [ { "aoVal": "A", "content": "$$2$$ " } ], [ { "aoVal": "B", "content": "$$64$$ " } ], [ { "aoVal": "C", "content": "$$79$$ " } ], [ { "aoVal": "D", "content": "$$96$$ " } ], [ { "aoVal": "E", "content": "$$131$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Operations through Formulas-> Difference of Two Squares Formula" ]
[ "Let\\textquotesingle s say that $x$ is the smaller of the two numbers. So the question is $$(x+1)+x\\textless100(x+1)^{2}-x^{2}=x^{2}+2x+1-x^{2}=2x+1$$. ~$$2x+1$$ is obviously odd, so the answer could be $$\\text{C}$$ or $$\\text{E}$$. $$2x+1=131$$ doesn\\textquotesingle t match with $$2x+1\\textless100$$, so the answer is $$79$$. Therefore, the answer is $$\\text{C}$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3006
339d23c6d10d423696ef81cebc0ee787
[ "其它" ]
3
single_choice
Two integers are inserted into the list $3,3,8,11,28$ to double its range. The mode and median remain unchanged. What is the maximum possible sum of the two additional numbers?
[ [ { "aoVal": "A", "content": "$$56$$ " } ], [ { "aoVal": "B", "content": "$$57$$ " } ], [ { "aoVal": "C", "content": "$$58$$ " } ], [ { "aoVal": "D", "content": "$$60$$ " } ], [ { "aoVal": "E", "content": "$$61$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "D " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3010
ab4a2fac752e41dda61332f79fdfc6ff
[]
1
single_choice
The $1986^{}\text{th}$ digit at the right of the decimal point in the decimal expression of $\dfrac{1}{7}$ is~\uline{~~~~~~~~~~}~.
[ [ { "aoVal": "A", "content": "$$2$$ " } ], [ { "aoVal": "B", "content": "$$4$$ " } ], [ { "aoVal": "C", "content": "$$5$$ " } ], [ { "aoVal": "D", "content": "$$7$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Word Problem Modules->Periodic Problems->Periodic Problems of Basic Permutation" ]
[ "$$\\frac{1}{7}=0.\\overline{142857}$$, it is a decimal which repeats in cycles of $6$. Every $6$\\textsuperscript{th}~digit is $7$. The $1986$\\textsuperscript{th} digit is $7$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3014
1cbf29a1824f450f8d5a03ab34502b3d
[ "其它" ]
1
single_choice
There are four more girls than boys in Mr. Tse\textquotesingle s class of 28 students. What is the ratio of number of girls to the number of boys in her class?
[ [ { "aoVal": "A", "content": "$4:3$ " } ], [ { "aoVal": "B", "content": "$3:2$ " } ], [ { "aoVal": "C", "content": "$7:4$ " } ], [ { "aoVal": "D", "content": "$2:1$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions" ]
[ "We can set up an equation with $x$ being the number of girls in the class. The number of boys in the class is equal to $x-4$. Since the total number of students is equal to 28 , we get $x+x-4=28$. Solving this equation, we get $x=16$. There are $16-4=12$ boys in our class, and our answer is $16: 12=$ (B) $4: 3$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3022
e79a938986014ae0b8681a678f3871c1
[ "其它" ]
0
single_choice
Cassandra is helping her mother to pack $$75$$ cupcakes. The boxes that her mother prepares can only fit $$7$$ cupcakes. She must ensure the box is full before she can use the next box. How many boxes she can fill up?
[ [ { "aoVal": "A", "content": "$$1$$ " } ], [ { "aoVal": "B", "content": "$$5$$ " } ], [ { "aoVal": "C", "content": "$$10$$ " } ], [ { "aoVal": "D", "content": "$$68$$ " } ], [ { "aoVal": "E", "content": "$$70$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division->Division of Whole Numbers" ]
[ "$$75\\div7=10R5$$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3025
825baef83b3e42d9afae2f1ee4e3100f
[]
1
single_choice
If $*abcd*=a\times d+b\times c$, then $*2543*=$~\uline{~~~~~~~~~~}~. ($2004$ Math League.com contest problem, $8$\textsuperscript{th} Grade, Question \#$33$)
[ [ { "aoVal": "A", "content": "$$14$$ " } ], [ { "aoVal": "B", "content": "$$22$$ " } ], [ { "aoVal": "C", "content": "$$26$$ " } ], [ { "aoVal": "D", "content": "$$120$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Operations with New Definition->Operating Directly" ]
[ "$*2543*=2\\times3+5\\times4=6+20=26$. So the answer is $\\rm C$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3029
b92f825aa14a463c884b78ba09d73857
[ "其它" ]
1
single_choice
Louis had $8$ sticks. He broke three of them into two pieces. How many sticks does he have now?
[ [ { "aoVal": "A", "content": "$$9$$ " } ], [ { "aoVal": "B", "content": "$$10$$ " } ], [ { "aoVal": "C", "content": "$$11$$ " } ], [ { "aoVal": "D", "content": "$$12$$ " } ], [ { "aoVal": "E", "content": "$$13$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "$8 + 3 = 11$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3034
33aa4abc98b3494aae488e50a499574b
[ "其它" ]
2
single_choice
If $3^{}p+3^{4}=90$, $2^{}r+44=76$, and $5^{3}+6^{}s=1421$, what is the product of $p$, $r$, and $s$? (2013 AMC 8 Problem, Question \#15)
[ [ { "aoVal": "A", "content": "$$27$$ " } ], [ { "aoVal": "B", "content": "$$40$$ " } ], [ { "aoVal": "C", "content": "$$50$$ " } ], [ { "aoVal": "D", "content": "$$70$$ " } ], [ { "aoVal": "E", "content": "$$90$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Power->Computing Powers->Exponentiation of Powers" ]
[ "Start with $3^{}p+3^{4}=90$. Then, change $3^{4}$ to $81$. Subtract from $81$ from both sides to get $3^{}p=9$ and see that $p$ is $2$. Now, solve for $r$. Since $2^{}r+44=76$, $2^{}r$ must equal $32$, so $r=5$. Now, solve for $s$. $5^{3}+6^{}s=1421$ can be simplified to $125+6^{}s=1421$, which simplifies further to $6^{}s=1296$. Therefore, $s=4$. $prs$ equals $2\\times5\\times4$ which equals $40$. So, the answer is $40$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3039
c7222249cad54e39affd54dd8fc0ed22
[ "其它" ]
1
single_choice
Hannah bought $$5$$ whole pizzas: $$1$$ for herself and $$1$$ for each of her $$4$$ students. Hannah sliced her pizza into $$5$$ equal parts and ate only $$3$$ slices. Student $$A$$ sliced his pizza into $$4$$ equal parts, but ate only $$3$$ slices. Student $$B$$ sliced his pizza into $$8$$ equal parts, but ate only $$7$$ slices. Student $$C$$ sliced her pizza into $$3$$ equal parts, but ate only $$2$$ slices. Student $$D$$ sliced her pizza into $$6$$ equal parts, but ate only $$3$$ slices. Who ate less pizza than Hannah?
[ [ { "aoVal": "A", "content": "Student $$A$$ " } ], [ { "aoVal": "B", "content": "Student $$B$$ " } ], [ { "aoVal": "C", "content": "Student $$C$$ " } ], [ { "aoVal": "D", "content": "Student $$D$$ " } ], [ { "aoVal": "E", "content": "Nobody " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions" ]
[ "All of them eat more than $$\\frac{1}{2}$$, except student $$D$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3042
0fe9ea5733434bb3999766d2af02150f
[ "其它" ]
1
single_choice
When Koko the Koala is awake, he eats $84$ grams of leaves per hour. He was awake for $2$ hours yesterday and $10$ hours today. How many grams of leaves did he eat in total in the two days? (adapted from 2014 Math Kangaroo Problem, Level 3-4, Question \#4)
[ [ { "aoVal": "A", "content": "$$840$$ " } ], [ { "aoVal": "B", "content": "$$168$$ " } ], [ { "aoVal": "C", "content": "$$672$$ " } ], [ { "aoVal": "D", "content": "$$1008$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "$84 \\times (10 + 2) = 84 \\times 10 + 84 \\times 2 = 840 + 168 = 1008$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3047
9d5b54d3ca0d4dfe980eac13b829b188
[]
1
single_choice
Which of the following is not an equivalent ratio of $$4:12$$?
[ [ { "aoVal": "A", "content": "$$1:3$$ " } ], [ { "aoVal": "B", "content": "$$2:6$$ " } ], [ { "aoVal": "C", "content": "$$8:36$$ " } ], [ { "aoVal": "D", "content": "$$32:96$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions->Proportions" ]
[ "Option A: $$1:3$$ $\\to$ $4:12$ Option B: $2:6$ $\\to$ $$1:3$$ $\\to$ $4:12$ Option C: $8:36$ $\\to$ $4:18$ Option D: $32:96$ $\\to$ $$1:3$$ $\\to$ $4:12$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3051
0c521e91f13a48f9b0b8207028cee9b7
[ "其它" ]
1
single_choice
In a math competition, each participant has a unique $5$-digit registration number of the form $\overline{BBCAC}$, where $0 \leq A \textless{} B\textless{} C \leq 9$ and $B$ is the average of $A$ and $C$. What is the maximum number of participant that can join this competition?
[ [ { "aoVal": "A", "content": "$$12$$ " } ], [ { "aoVal": "B", "content": "$$16$$ " } ], [ { "aoVal": "C", "content": "$$18$$ " } ], [ { "aoVal": "D", "content": "$$20$$ " } ], [ { "aoVal": "E", "content": "$$25$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "D " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3059
384db7f8e417484398459f2da518902f
[ "其它" ]
2
single_choice
For $\triangle ABC$, all its side lengths are integers. The primeter of $\triangle ABC$ with a side of length $14$ and a side length of $8$ is at least .
[ [ { "aoVal": "A", "content": "$$25$$ " } ], [ { "aoVal": "B", "content": "$$26$$ " } ], [ { "aoVal": "C", "content": "$$27$$ " } ], [ { "aoVal": "D", "content": "$$28$$ " } ], [ { "aoVal": "E", "content": "$$29$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s+8\\textgreater14$. Therefore, $P\\textgreater14+14$. The least integer value of $P$ is $29$ " ]
E
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3060
2f1912f582c94b3cb9fdf661a69a062b
[ "其它" ]
1
single_choice
There are two positive integers, $$x$$ and $$y$$. $$x$$ equals to $$3^{2}$$, and $$y$$ is the base of $$5^{3}$$. What is the product of $$x$$ and $$y$$?
[ [ { "aoVal": "A", "content": "$15$ " } ], [ { "aoVal": "B", "content": "$45$ " } ], [ { "aoVal": "C", "content": "$90$ " } ], [ { "aoVal": "D", "content": "$1125$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Power->Computing Powers->Exponentiation of Powers" ]
[ "$$x=3^{2}=9$$ $$5$$ cubed is $$5^{3}$$. And the base is $$5$$. So, $$x\\cdot y=9\\times 5=45$$ " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3061
0c5c6aa8452b43919bde5a93ed8675f6
[ "其它" ]
1
single_choice
SASMO 2016 P2 Q5 What number does () stands for?
[ [ { "aoVal": "A", "content": "$$2$$ " } ], [ { "aoVal": "B", "content": "$$4$$ " } ], [ { "aoVal": "C", "content": "$$6$$ " } ], [ { "aoVal": "D", "content": "$$8$$ " } ], [ { "aoVal": "E", "content": "$$10$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Operations with New Definition->Finding Patterns->Encryption and Decryption" ]
[ "banana = 32-24= 8 A + 8 = 12 A = 4 " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3063
41857e581e2a46869b29dafc95600556
[ "其它" ]
2
single_choice
For $\triangle ABC$, all its side lengths are integers. The perimeter of $\triangle ABC$ with a side of length $14$ and a side length of $8$ is at least .
[ [ { "aoVal": "A", "content": "$$25$$ " } ], [ { "aoVal": "B", "content": "$$26$$ " } ], [ { "aoVal": "C", "content": "$$27$$ " } ], [ { "aoVal": "D", "content": "$$28$$ " } ], [ { "aoVal": "E", "content": "$$29$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s+8\\textgreater14$. Therefore, $P\\textgreater14+14$. The least integer value of $P$ is $29$ " ]
E
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3065
1ce6aa2cc04e4ae0a78ef22986778c89
[ "其它" ]
1
single_choice
$2018$ is an interesting number. This is because when we add the first digit and the last digit, we will get the reverse of the middle two digits. Which of the options below is also an interesting number?
[ [ { "aoVal": "A", "content": "$$3014$$ " } ], [ { "aoVal": "B", "content": "$$3129$$ " } ], [ { "aoVal": "C", "content": "$$4319$$ " } ], [ { "aoVal": "D", "content": "$$2017$$ " } ], [ { "aoVal": "E", "content": "$$4913$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers" ]
[ "NA " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3073
187d23b145854fc3af538ceafbb56d10
[ "其它" ]
0
single_choice
Given: $a-b\textgreater a$ and $a+b\textless b$. Which of the following must be true?~\uline{~~~~~~~~~~}~ $I$. $a b$ is negative $II$. $a+b$ is negative $III$. $a-b$ is negative
[ [ { "aoVal": "A", "content": "$I$ only " } ], [ { "aoVal": "B", "content": "$I$ and $III$ only " } ], [ { "aoVal": "C", "content": "$II$ only " } ], [ { "aoVal": "D", "content": "$I$, $II$, $III$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "$a-b\\textgreater a$ then $b\\textless0$ $a+b\\textless b$ then $a\\textless0$. So both $a$ and $b$ are negative. $I$ is false, since the product will be positive. $II$ is true since the sum of two negative numbers is negative. $III$ is false because if $a=-1$ and $b=-2$ then $a-b$ is positive. Only $II$ is true. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3082
0c99a520a2684252805a3492987c0a25
[ "其它" ]
3
single_choice
What is the remainder when $2^{2023}+2023$ is divided by $2^{20}+1$? (Adapted From 2020 AMC 10B Problems, Question \#22)
[ [ { "aoVal": "A", "content": "$$2015$$ " } ], [ { "aoVal": "B", "content": "$$2^{5}$$ " } ], [ { "aoVal": "C", "content": "$$2023$$ " } ], [ { "aoVal": "D", "content": "$$2048$$ " } ], [ { "aoVal": "E", "content": "$$20$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "Let $x=2^{20}$. We are now looking for the remainder of $\\frac{8x^{101}+2023}{x+1}$. By Polynomial Remainder Theorem, the remainder is $8\\times (-1)^{101} + 2023 = 2015$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3084
7dc26cf49b234cd4995ea03f3dcb57c7
[]
1
single_choice
The last four digits in Andy\textquotesingle s ID card are $2025$. What is the the difference between the largest and the smallest digit in $2025$?~(adapted from $$2011$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$7$$)
[ [ { "aoVal": "A", "content": "$$2$$ " } ], [ { "aoVal": "B", "content": "$$3$$ " } ], [ { "aoVal": "C", "content": "$$4$$ " } ], [ { "aoVal": "D", "content": "$$5$$ " } ], [ { "aoVal": "E", "content": "$$0$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Addition and Subtraction ->Addition of Whole Numbers->Addition in Horizontal Form" ]
[ "The largest digit is $5$, and the smallest digit is $0$. $5-0=5$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3085
1cfbee250a164e71b742fb4b4f7dd1d0
[ "其它" ]
1
single_choice
Let $a$ and $b$ be relatively prime positive integers with $a\textgreater b\textgreater0$ and $\frac{a^{3}-b^{3}}{(a-b)^{3}}=\frac{73}{3}$. What is $a-b$?
[ [ { "aoVal": "A", "content": "$$1$$ " } ], [ { "aoVal": "B", "content": "$$2$$ " } ], [ { "aoVal": "C", "content": "$$3$$ " } ], [ { "aoVal": "D", "content": "$$4$$ " } ], [ { "aoVal": "E", "content": "$$5$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions" ]
[ "Slightly expanding, we have that $\\frac{(a-b)\\left(a^{2}+a b+b^{2}\\right)}{(a-b)(a-b)(a-b)}=\\frac{73}{3}$. Canceling the $(a-b)$, cross multiplying, and simplifying, we obtain that $0=70 a^{2}-149 a b+70 b^{2}$. Dividing everything by $b^{2}$, we get that $$ 0=70\\left(\\frac{a}{b}\\right)^{2}-149\\left(\\frac{a}{b}\\right)+70 \\text {. } $$ Applying the quadratic formula and following the restriction that $a\\textgreater b\\textgreater0$ $$ \\frac{a}{b}=\\frac{10}{7} \\text {. } $$ Hence, $7 a=10 b$. Since they are relatively prime, $a=10, b=7$. $$ 10-7= 3 \\text {. } $$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3086
0ca2c393bd9448e08058dc264eb35c99
[ "其它" ]
1
single_choice
Which number has to be subtracted from $17$ in order to obtain $-33$? (Adapted from 2017 Math Kangaroo Problem, Level 7-8, Question \#3)
[ [ { "aoVal": "A", "content": "$$-50$$ " } ], [ { "aoVal": "B", "content": "$$-16$$ " } ], [ { "aoVal": "C", "content": "$$16$$ " } ], [ { "aoVal": "D", "content": "$$40$$ " } ], [ { "aoVal": "E", "content": "$$50$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Mixed Operations" ]
[ "$17-50=-33$, so the answer is $E$. " ]
E
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3090
462dbfeddd304192b5a0729c40eec657
[ "其它" ]
0
single_choice
Fill in the blank:~\uline{~~~~~~~~~~}~is $$3$$ tens $$7$$ ones less than $$4$$ tens $$6$$ ones.
[ [ { "aoVal": "A", "content": "$$9$$ " } ], [ { "aoVal": "B", "content": "$$19$$ " } ], [ { "aoVal": "C", "content": "$$73$$ " } ], [ { "aoVal": "D", "content": "$$83$$ " } ], [ { "aoVal": "E", "content": "None of the above " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "$$3$$ tens $$7$$ ones: $$37$$ $$4$$ tens $$6$$ ones: $$46$$ less than: $$46-37=9$$ " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3093
3cf571d3965345a4bc833ed99c9cec48
[ "其它" ]
1
single_choice
There were $$16$$ monkeys in total in the animal school. After the whistle, they arranged themselves into $$8$$ rows. How many monkeys were there in each row after the whistle? (Adapted from 2005 Math Kangaroo Problem, Level 3-4, Question \#4)
[ [ { "aoVal": "A", "content": "$$1$$ " } ], [ { "aoVal": "B", "content": "$$2$$ " } ], [ { "aoVal": "C", "content": "$$3$$ " } ], [ { "aoVal": "D", "content": "$$4$$ " } ], [ { "aoVal": "E", "content": "$$5$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "There were $$16 \\div 8 = 2$$ monkeys in each row. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3097
462ffa8d8796404ab3306171f72c5899
[ "其它" ]
2
single_choice
Find all values of $x$ such that $\textbar3 x+12\textbar\textless9$ and $\textbar x+2\textbar\textless\textbar-3 x-6\textbar$.~\uline{~~~~~~~~~~}~
[ [ { "aoVal": "A", "content": "$x\\textless-2$ " } ], [ { "aoVal": "B", "content": "$-7\\textless x\\textless-1$ " } ], [ { "aoVal": "C", "content": "$-7\\textless x\\textless-2$ " } ], [ { "aoVal": "D", "content": "$-7\\textless x\\textless-1 ; x \\neq-2$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "Based on the first inequality, we know that $-9\\textless3 x+12\\textless9$ because $3 x+2$ must be less than 9 units away from zero. We can subtract 12 from all three parts of the inequality to arrive at $-21\\textless3 x\\textless-3 \\rightarrow-7\\textless x\\textless-1$. From the second inequality we can rewrite $\\textbar-3 x-6\\textbar$ as $\\textbar3 x+6\\textbar=3\\textbar x+2\\textbar$ because they must be equal. The second inequality must be true for all numbers except for when $\\textbar x+2\\textbar=0$, or when $x=-2$. Thus the answer includes all numbers from $-7$ to $-1$ with the exception of $-2$. The answer is $\\mathbf{D}$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3099
104cb24c29ac4e95a5906515857ad9c5
[ "其它" ]
2
single_choice
For $\triangle ABC$, all its side lengths are integers. The perimeter of $\triangle ABC$ with a side of length $3$ and a side length of $4$ is at least .
[ [ { "aoVal": "A", "content": "$$7$$ " } ], [ { "aoVal": "B", "content": "$$8$$ " } ], [ { "aoVal": "C", "content": "$$9$$ " } ], [ { "aoVal": "D", "content": "$$12$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s+3\\textgreater4$. Therefore, $P\\textgreater4+4$. The least integer value of $P$ is $9$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3101
1050c8cd59ef4048b090596ce767379b
[ "其它" ]
1
single_choice
Suppose that $x$ and $y$ are nonzero real numbers such that $\frac{3 x+y}{x-3 y}=-2$. What is the value of $\frac{x+3 y}{3 x-y}$?
[ [ { "aoVal": "A", "content": "$$-3$$ " } ], [ { "aoVal": "B", "content": "$$-1$$ " } ], [ { "aoVal": "C", "content": "$$1$$ " } ], [ { "aoVal": "D", "content": "$$2$$ " } ], [ { "aoVal": "E", "content": "$$3$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Proportional Equations" ]
[ "Rearranging, we find $3 x+y=-2 x+6 y$, or $5 x=5 y \\Longrightarrow x=y$. Substituting, we can convert the second equation into $\\frac{x+3 x}{3 x-x}=\\frac{4 x}{2 x}= 2$ More step-by-step explanation: $$ \\begin{aligned} \\&\\frac{3 x+y}{x-3 y}=-2 \\textbackslash\\textbackslash{} \\&3 x+y=-2(x-3 y) \\textbackslash\\textbackslash{} \\&3 x+y=-2 x+6 y \\textbackslash\\textbackslash{} \\&5 x=5 y \\textbackslash\\textbackslash{} \\&x=y \\textbackslash\\textbackslash{} \\&\\frac{x+3 y}{3 x-y}=\\frac{1+3(1)}{3(1)-1}=\\frac{4}{2}=2 \\end{aligned} $$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3105
0cd694cef6ec494b8071562f50e7d515
[]
1
single_choice
Compare these fractions. $$\frac{8}{31}$$~\uline{~~~~~~~~~~}~$$\frac{4}{15}$$, ~$$\frac{9}{61}$$~\uline{~~~~~~~~~~}~$$\frac{3}{22}$$
[ [ { "aoVal": "A", "content": "$$\\textgreater$$, $$\\textgreater$$ " } ], [ { "aoVal": "B", "content": "$$\\textgreater$$, $$\\textless$$ " } ], [ { "aoVal": "C", "content": "$$\\textless$$, $$\\textgreater$$ " } ], [ { "aoVal": "D", "content": "$$\\textless$$, $$\\textless$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Comparing, Ordering and Estimating->Comparing and Ordering" ]
[ "$$\\frac{8}{31}\\textless\\frac{8}{30}$$;~$$\\frac{9}{61}\\textgreater\\frac{9}{66}$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3109
2a9f364dcd2c4697a2002751ad9c9a06
[]
1
single_choice
Compare these fractions. $$\frac{3}{7}$$~\uline{~~~~~~~~~~}~$$\frac{5}{9}$$, $$\frac{5}{8}$$~\uline{~~~~~~~~~~}~$$\frac{7}{11}$$
[ [ { "aoVal": "A", "content": "$$\\textgreater$$, $$\\textgreater$$ " } ], [ { "aoVal": "B", "content": "$$\\textgreater$$, $$\\textless$$ " } ], [ { "aoVal": "C", "content": "$$\\textless$$, $$\\textgreater$$ " } ], [ { "aoVal": "D", "content": "$$\\textless$$, $$\\textless$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Comparing, Ordering and Estimating->Comparing and Ordering" ]
[ "$$\\frac{27}{63}\\textless\\frac{35}{63}$$;~$$\\frac{55}{88}\\textless\\frac{56}{88}$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3120
2aa671beb13e4c0e987bf38779f6f986
[]
1
single_choice
If $ a◆b$ means $(a\times b)+b$ , then $(2◆3)◆4$ has the value.
[ [ { "aoVal": "A", "content": "$$45$$ " } ], [ { "aoVal": "B", "content": "$$40$$ " } ], [ { "aoVal": "C", "content": "$$16$$ " } ], [ { "aoVal": "D", "content": "$$9$$ " } ], [ { "aoVal": "E", "content": "$$8$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Operations with New Definition->Operating Directly" ]
[ "If $a◆b$~ represents $(a\\times b)+b$ , $2◆3=(2\\times3)+3=9,9◆4=(9\\times4)+4=40$ . " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3125
2aa8627cef2b444dbb189c1d669cf4dd
[ "其它" ]
3
single_choice
(2) Eddie had 120 dollars as his pocket money, and spent $$ \frac{3}{4} $$of it. How much money is left?
[ [ { "aoVal": "A", "content": "$$30$$ " } ], [ { "aoVal": "B", "content": "$$60$$ " } ], [ { "aoVal": "C", "content": "$$90$$ " } ], [ { "aoVal": "D", "content": "$$120$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions" ]
[ "left!!!not spent! So you need to calculate the fraction of left money. Then use T*F=C " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3129
107bd421b05c488a8b8c4edbe9555001
[]
1
single_choice
Divide $$2$$、$$3$$、$$24$$、$$33$$、$$55$$ and $$60$$ into two groups with 3 numbers in each group to make the product of numbers in each group the same, so the product is.
[ [ { "aoVal": "A", "content": "$$3630$$ " } ], [ { "aoVal": "B", "content": "$$1584$$ " } ], [ { "aoVal": "C", "content": "$$3960$$ " } ], [ { "aoVal": "D", "content": "$$2880$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Power->Computing Powers->Power of Products" ]
[ "$$2=2$$, $$3=3$$, $$24=2\\times 2\\times 2\\times 3$$, $$33=11\\times 3$$, $$55=11\\times 5$$, $$60=2\\times 2\\times 3\\times 5$$, $$2\\times 60\\times 33=24\\times 55\\times 3$$, $$\\textasciitilde\\textasciitilde\\textasciitilde\\textasciitilde2\\times 60\\times 33$$ $$=(2\\times 33)\\times 60$$ $$=66\\times 60$$ $$=3960$$. $$\\text{C}$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3130
2aaab2c7197449e39c7d48d630f9ad82
[ "其它" ]
1
single_choice
Which of the following integers cannot be written as the sum of four consecutive odd integers? (2015 AMC 8 Problems, Question \#14)
[ [ { "aoVal": "A", "content": "$$16$$ " } ], [ { "aoVal": "B", "content": "$$40$$ " } ], [ { "aoVal": "C", "content": "$$72$$ " } ], [ { "aoVal": "D", "content": "$$100$$ " } ], [ { "aoVal": "E", "content": "$$200$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables" ]
[ "Let our $4$ numbers be $n, n+2, n+4, n+6$, where $n$ is odd. Then our sum is $4 n+12$. The only answer choice that cannot be written as $4 n+12$, where $n$ is odd, is (D) 100 . " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3133
4f79338751d14373824ad19253db5cda
[]
1
single_choice
$$100-99+98-97+96-95+\cdots +4-3+2-1$$.
[ [ { "aoVal": "A", "content": "$$20$$ " } ], [ { "aoVal": "B", "content": "$$40$$ " } ], [ { "aoVal": "C", "content": "$$50$$ " } ], [ { "aoVal": "D", "content": "$$80$$ " } ], [ { "aoVal": "E", "content": "$$100$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Addition and Subtraction " ]
[ "$$\\begin{eqnarray}\\&\\&\\left( 100-99 \\right)+\\left( 98-97 \\right)\\cdots +\\left( 4-3 \\right)+\\left( 2-1 \\right)\\textbackslash\\textbackslash{} \\&=\\&50\\times 1\\textbackslash\\textbackslash{} \\&=\\&50.\\end{eqnarray}$$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3135
2f45ea48881c49ce935b004458a4e070
[]
1
single_choice
Of the following, which has a value different from the others?
[ [ { "aoVal": "A", "content": "$$40\\times 50$$ " } ], [ { "aoVal": "B", "content": "$$4\\times 5000$$ " } ], [ { "aoVal": "C", "content": "$$50\\times 400$$ " } ], [ { "aoVal": "D", "content": "$$40\\times 500$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "To see which value is different, count the total number of $$0$$\\textquotesingle s in each product. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3148
18d151cf57304f1faabe74ceb029b2d3
[]
1
single_choice
$$12 \times \left( \frac{1}{2} \times \frac{1}{3} \times \frac{1}{4}\right)=$$.
[ [ { "aoVal": "A", "content": "$$72$$ " } ], [ { "aoVal": "B", "content": "$$13$$ " } ], [ { "aoVal": "C", "content": "$$\\frac{4}{3}$$ " } ], [ { "aoVal": "D", "content": "$$\\frac{1}{2}$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Operations of Fractions" ]
[ "$$12 \\times \\left( \\frac{1}{2} \\times \\frac{1}{3} \\times \\frac{1}{4}\\right)$$ $$=\\left(12 \\times \\frac{1}{2}\\right) \\times \\frac{1}{3} \\times \\frac{1}{4}$$ $$=6 \\times \\frac{1}{3} \\times \\frac{1}{4}$$ $$=2 \\times \\frac{1}{4}$$ $$= \\frac{2}{4}$$ $$=\\frac{1}{2}$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3157
149f548c79214e2e96d267efa3cd3e51
[ "其它" ]
2
single_choice
For $\triangle ABC$, all its side lengths are integers. The primeter of $\triangle ABC$ with a side of length $3$ and a side length of $4$ is at least .
[ [ { "aoVal": "A", "content": "$$7$$ " } ], [ { "aoVal": "B", "content": "$$8$$ " } ], [ { "aoVal": "C", "content": "$$9$$ " } ], [ { "aoVal": "D", "content": "$$12$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s+3\\textgreater4$. Therefore, $P\\textgreater4+4$. The least integer value of $P$ is $9$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3158
1d3939fc360b4acf9bb5f701720ee8d3
[]
1
single_choice
$$(60 \div 5)\times4 =$$. 
[ [ { "aoVal": "A", "content": "$$3$$ " } ], [ { "aoVal": "B", "content": "$$16$$ " } ], [ { "aoVal": "C", "content": "$$48$$ " } ], [ { "aoVal": "D", "content": "$$96$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "$$(60\\div5)\\times4 = 12 \\times4 =48$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3170
10bab04c693d45a682c2dd25c9be35be
[]
1
single_choice
The fraction $$\dfrac{214}{263}$$ keeps the same value when both its numerator and denominator are~\uline{~~~~~~~~~~}~.
[ [ { "aoVal": "A", "content": "multiplied by $$2~ $$ " } ], [ { "aoVal": "B", "content": "increased by $$2$$ " } ], [ { "aoVal": "C", "content": "decreased by $$2$$ " } ], [ { "aoVal": "D", "content": "$$ $$squared$$ $$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Basic Understanding of Fractions" ]
[ "The problem is about the basic property of fractions, namely, multiplying or dividing the numerator and denominator by the same number (except $$0$$), the value of the fraction is unchanged. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3174
871a91f435174c6d874964fe2a512898
[ "其它" ]
2
single_choice
For $\triangle ABC$, all its side lengths are integer. The primeter of $\triangle ABC$ with a side of length $12$ and a side length of $7$ is at least .
[ [ { "aoVal": "A", "content": "$$24$$ " } ], [ { "aoVal": "B", "content": "$$25$$ " } ], [ { "aoVal": "C", "content": "$$26$$ " } ], [ { "aoVal": "D", "content": "$$27$$ " } ], [ { "aoVal": "E", "content": "$$28$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s+7\\textgreater12$. $P=s+7+12\\textgreater12+12$. Therefore, $P\\textgreater24+1=25$ " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3176
10c410e94f714a968414b9fe9b49ddfd
[]
1
single_choice
$$10\times20\times30\times40=24\times$$.
[ [ { "aoVal": "A", "content": "$$10^{3}$$ " } ], [ { "aoVal": "B", "content": "$$10^{4}$$ " } ], [ { "aoVal": "C", "content": "$$10^{5}$$ " } ], [ { "aoVal": "D", "content": "$$10^{6}$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "$$10\\times20\\times30\\times40=(1\\times2\\times3\\times4)\\times10^{4}=24\\times10^{4}$$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3178
14b9a6231ea34a369555235854cd782b
[ "其它" ]
2
single_choice
What is the correct ordering of the three answers from $\frac5{19}\div \frac{25}{38}$, $1\frac12 \div \frac{15}8$, and $\frac74 \div \frac{35}{12}$, in increasing order? (adapted from 2012 AMC 8 Problems, Question \#20)
[ [ { "aoVal": "A", "content": "$\\frac5{19}\\div \\frac{25}{38}$ \\textless~$1\\frac12 \\div \\frac{15}8$ \\textless{} $\\frac74 \\div \\frac{35}{12}$ " } ], [ { "aoVal": "B", "content": "$\\frac74 \\div \\frac{35}{12}$ \\textless~$1\\frac12 \\div \\frac{15}8$ \\textless~$\\frac5{19}\\div \\frac{25}{38}$ " } ], [ { "aoVal": "C", "content": "$1\\frac12 \\div \\frac{15}8$ \\textless{} $\\frac74 \\div \\frac{35}{12}$ \\textless~$\\frac5{19}\\div \\frac{25}{38}$ " } ], [ { "aoVal": "D", "content": "$\\frac5{19}\\div \\frac{25}{38}$ \\textless{} $\\frac74 \\div \\frac{35}{12}$ \\textless~$1\\frac12 \\div \\frac{15}8$ " } ], [ { "aoVal": "E", "content": "$\\frac74 \\div \\frac{35}{12}$ \\textless~$\\frac5{19}\\div \\frac{25}{38}$ \\textless~$1\\frac12 \\div \\frac{15}8$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Operations of Fractions->Division of Fractions" ]
[ "$\\frac5{19}\\div \\frac{25}{38}=\\frac25$ ~ $\\frac74 \\div \\frac{35}{12}=\\frac35$ $1\\frac12 \\div \\frac{15}8=\\frac45$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3184
0d8645b641864aaf89ccbabd1766f528
[]
0
single_choice
Choose the answer in the simplest form. $$\frac{9}{4}\times \frac{8}{27}=$$.
[ [ { "aoVal": "A", "content": "$$\\frac{72}{108}$$ " } ], [ { "aoVal": "B", "content": "$$\\frac{18}{27}$$ " } ], [ { "aoVal": "C", "content": "$$\\frac{8}{12}$$ " } ], [ { "aoVal": "D", "content": "$$\\frac{2}{3}$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions" ]
[ "$$\\frac{9}{4}\\times \\frac{8}{27}=\\frac{2}{3}$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3188
8adb1db084c44752a477a8050b885e20
[]
1
single_choice
In the arithmetic sequence $3$, $7$, $11$, $15$, $\cdots$ , the $26$\textsuperscript{th} number is.
[ [ { "aoVal": "A", "content": "$$103$$ " } ], [ { "aoVal": "B", "content": "$$107$$ " } ], [ { "aoVal": "C", "content": "$$111$$ " } ], [ { "aoVal": "D", "content": "$$115$$ " } ], [ { "aoVal": "E", "content": "$$119$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Arithmetic Sequences" ]
[ "$3+4\\times(26-1)=103$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3190
e7a739171d584f8286b66dae9c61810d
[]
1
single_choice
If a whole number is multiplied by itself, the ones\textquotesingle{} digit of the product \emph{cannot} be.
[ [ { "aoVal": "A", "content": "$$1$$ " } ], [ { "aoVal": "B", "content": "$$5$$ " } ], [ { "aoVal": "C", "content": "$$7$$ " } ], [ { "aoVal": "D", "content": "$$9$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Power->Computing Powers" ]
[ "If a whole number is multiplied by itself, the ones\\textquotesingle{} digit of the product could be $$1 (1\\times1)$$ or $$5 (5\\times5)$$ or $$9 (3\\times3)$$, but not $$7$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3207
1910c45a41094f67a6aefa7c4f2d8ab9
[ "其它" ]
1
single_choice
Bob: " Hi, Stanley. What is the coefficient of the variable in this algebraic expression $3x^{2}-4$?" Stanley:" I can give you a hint. The value of the coefficient is $7$ more than the constant." Stanley\textquotesingle s hint is~\uline{~~~~~~~~~~}~and the coefficient of the variable is~\uline{~~~~~~~~~~}~.
[ [ { "aoVal": "A", "content": "correct, $3$ " } ], [ { "aoVal": "B", "content": "correct, $-4$ " } ], [ { "aoVal": "C", "content": "incorrect, $3$ " } ], [ { "aoVal": "D", "content": "incorrect, $4$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Equivalent Substitution->Algebraic Expressions" ]
[ "Constant: $-4$ Coefficient of the variable: $3$ " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3208
3892760088974be3809057c4a34f9ea5
[ "其它" ]
1
single_choice
Gilda has a bag of marbles. She gives $20 \textbackslash\%$ of them to her friend Pedro. Then Gilda gives $25 \textbackslash\%$ of what is left to another friend, Ebony. Finally, Gilda gives $5 \textbackslash\%$ of what is now left in the bag to her brother Jimmy. What percentage of her original bag of marbles does Gilda have left for herself? (adapted 2019 AMC 8, Question \#8)
[ [ { "aoVal": "A", "content": "$$95\\textbackslash\\%$$ " } ], [ { "aoVal": "B", "content": "$33\\textbackslash\\%$ " } ], [ { "aoVal": "C", "content": "$$45\\textbackslash\\%$$ " } ], [ { "aoVal": "D", "content": "$$57\\textbackslash\\%$$ " } ], [ { "aoVal": "E", "content": "$$63\\textbackslash\\%$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Percentage Calculation" ]
[ "After Gilda gives $20 \\textbackslash\\%$ of the marbles to Pedro, she has $80 \\textbackslash\\%$ of the marbles left. If she then gives $25 \\textbackslash\\%$ of what\\textquotesingle s left to Ebony, she has $(0.75 * 0.8)=60 \\textbackslash\\%$ of what she had at the beginning. Finally, she gives $5 \\textbackslash\\%$ of what\\textquotesingle s left to her brother, so she has $(0.6 * 0.95)$ (D) $57\\textbackslash\\%$~ of what she had in the beginning left. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3210
10fd6979282b4979b9957a12921a5454
[]
1
single_choice
Given that $$x\otimes y=6\times x-5\times y$$, find $$7\otimes 6$$.
[ [ { "aoVal": "A", "content": "$$12$$ " } ], [ { "aoVal": "B", "content": "$$13$$ " } ], [ { "aoVal": "C", "content": "$$42$$ " } ], [ { "aoVal": "D", "content": "$$30$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Operations with New Definition->Operating Directly" ]
[ "$$7\\otimes 6=6\\times 7-5\\times 6=12$$, so $$\\text{A}$$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3212
389341fb19f24bb9854c00120b1497dd
[ "其它" ]
2
single_choice
For $\triangle ABC$, all its side lengths are integer. The primeter of $\triangle ABC$ with a side of length $12$ and a side length of $7$ is at least .
[ [ { "aoVal": "A", "content": "$$24$$ " } ], [ { "aoVal": "B", "content": "$$25$$ " } ], [ { "aoVal": "C", "content": "$$26$$ " } ], [ { "aoVal": "D", "content": "$$27$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s+7\\textgreater12$. $P=s+7+12\\textgreater12+12$. Therefore, $P\\textgreater24+1=25$ " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3213
1913a1ef9a3f4a85b785d99103fe3aec
[ "其它" ]
1
single_choice
A slug called Glug eats $$2$$ tomatoes for every $$3$$ strawberries. Yesterday it had eaten $$35$$ tomatoes and strawberries altogether. How many tomatoes did it eat?
[ [ { "aoVal": "A", "content": "$$5$$ " } ], [ { "aoVal": "B", "content": "$$7$$ " } ], [ { "aoVal": "C", "content": "$$14$$ " } ], [ { "aoVal": "D", "content": "$$15$$ " } ], [ { "aoVal": "E", "content": "$$21$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions" ]
[ "$$35\\times \\frac {2} {2+3} = 14$$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3223
2661bd89429e4781b774bf3f04b5ee94
[ "其它" ]
4
single_choice
How many perfect cubes lie between $2^{2}+1$ and $2^{8}+1$, inclusive? (Adapted from 2018 AMC 8 Problem, Question \#25)
[ [ { "aoVal": "A", "content": "$$2$$ " } ], [ { "aoVal": "B", "content": "$$3$$ " } ], [ { "aoVal": "C", "content": "$$4$$ " } ], [ { "aoVal": "D", "content": "$$5$$ " } ], [ { "aoVal": "E", "content": "$$6$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Power->Computing Powers->Exponentiation of Powers" ]
[ "$2^{2}+1=5$, $2^{8}+1=257$. $2^{3}=8$, $3^{3}=27$, $4^{3}=64$, $5^{3}=125$, $6^{3}=216$. Thus, the answer is $5$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3228
1922af64ee39418faf2982a09de961a8
[]
1
single_choice
Steven subtracts the units digit from the tens digit for each two-digit number. He then finds the sum of all his answers. What is the value of Steven\textquotesingle s sum?
[ [ { "aoVal": "A", "content": "$$30$$ " } ], [ { "aoVal": "B", "content": "$$45$$ " } ], [ { "aoVal": "C", "content": "$$55$$ " } ], [ { "aoVal": "D", "content": "$$90$$ " } ], [ { "aoVal": "E", "content": "$$100$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Arithmetic Sequences" ]
[ "The sum of all the tens digits is $$\\left(1+2+3+4+5 +6 +7+8+9\\right)\\times10$$. The sum of all the units digits is $$\\left(0 + 1+2+3 +4+5 +6 +7+8+9\\right)\\times9$$. Therefore Steven\\textquotesingle s sum is $$\\left(1+2+3 +4+5+6+7+8+9\\right)\\times1=45$$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3229
a6bbd2266dd14466b6278a5aa480f07a
[]
0
single_choice
The product of two different nonzero integers cannot be.
[ [ { "aoVal": "A", "content": "prime  " } ], [ { "aoVal": "B", "content": "zero  " } ], [ { "aoVal": "C", "content": "even  " } ], [ { "aoVal": "D", "content": "composite  " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "The product of two different nonzero integers can never be $$0$$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3237
112339a3eed14f7a92441f199fdbd2ba
[ "其它" ]
1
single_choice
Bob bought three kinds of meat: pork, beef and chicken with the total cost of $152. The ratio of the weight of pork, beef and chicken is~$2:4:3$. The ratio of the price per pound of pork, beef and chicken is~$6:5:2$. What is the sum of the last digits of the cost of each kind in dollars?
[ [ { "aoVal": "A", "content": "$$8$$ " } ], [ { "aoVal": "B", "content": "$$10$$ " } ], [ { "aoVal": "C", "content": "$$12$$ " } ], [ { "aoVal": "D", "content": "$$15$$ " } ], [ { "aoVal": "E", "content": "$$16$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions" ]
[ "Let~$x,\\textbackslash{} y\\textbackslash{} and\\textbackslash{} z$~be the weight of pork, beef and chicken, respectively. ~$\\textbackslash{} x:y:z=2:4:3$~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ (1) The ratio of the price will be~$\\left( 6x\\right):\\left( 5y\\right):\\left( 2z\\right).$ The costs of pork, beef and chicken are~$A,B\\textbackslash{} and\\textbackslash{} C,$~respectively. ~$A=\\dfrac{6x}{6x+5y+2z}\\times152$~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~(2) From (1), we get: ~$y=2x,\\textbackslash{} and\\textbackslash{} z=\\dfrac{3}{2}x$~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~(3) (2) becomes:~$A=\\dfrac{6x}{6x+5\\left( 2x\\right)+2\\times\\dfrac{3}{2}x}\\times152=\\dfrac{6x}{19x}\\times152=48$ Similarly,~$B=\\dfrac{5y}{6x+5y+2z}\\times152=\\dfrac{5y}{19x}\\times152=\\dfrac{10x}{19x}\\times152=80.$ And~$C=\\dfrac{2z}{6x+5y+2z}\\times152=\\dfrac{2z}{19x}\\times152=\\dfrac{3x}{19x}\\times152=24.$ Pork costs $48 per pound, beef costs $80, and chicken costs $24. The sum of the last digits of the costs is 8+0+4=12. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3239
8ae1f9550be84771a09fb8060f539cde
[]
0
single_choice
$$1000\text{m}$$ per second $$=$$$$\text{km}$$ per hour.
[ [ { "aoVal": "A", "content": "$$60$$ " } ], [ { "aoVal": "B", "content": "$$360$$ " } ], [ { "aoVal": "C", "content": "$$3600$$ " } ], [ { "aoVal": "D", "content": "$$6000$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Unit Conversion->Converting between Compound Units" ]
[ "$$1000\\text{m/s}=1\\text{km/s}=3600\\text{km/hr}$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3241
266d6bbe3d344f59ba5f1e69b7aa9406
[]
1
single_choice
Solve the equation: $$16\times 25-13\left( 3x+2 \right)=179$$.
[ [ { "aoVal": "A", "content": "$$4$$ " } ], [ { "aoVal": "B", "content": "$$5$$ " } ], [ { "aoVal": "C", "content": "$$6$$ " } ], [ { "aoVal": "D", "content": "$$7$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Equivalent Substitution->Algebraic Expressions" ]
[ "$$39x=400-26-179$$ $$\\textasciitilde\\textasciitilde\\textasciitilde\\textasciitilde x=5$$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3252
15123010499b4516bea8a0dda21162d9
[ "其它" ]
0
single_choice
Find the missing term in the following sequence: $$1, 2, 4, 7,~\uline{~~~~~~~~~~}~, 16$$.
[ [ { "aoVal": "A", "content": "$$10$$ " } ], [ { "aoVal": "B", "content": "$$11$$ " } ], [ { "aoVal": "C", "content": "$$12$$ " } ], [ { "aoVal": "D", "content": "$$13$$ " } ], [ { "aoVal": "E", "content": "$$14$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Patterns in Number Sequences" ]
[ "The number sequence are in the pattern of $$+1, +2, +3, +4, +5, \\cdots $$ " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3254
1d8b25027f93406ab007abfe91add3c8
[ "其它" ]
2
single_choice
On Kangaroo planet each kangyear has 20 kangmonths and each kangmonth has 6 kangweeks, How many kangweeks are there in one quarter of a kangyear?
[ [ { "aoVal": "A", "content": "$$9$$ " } ], [ { "aoVal": "B", "content": "$$30$$ " } ], [ { "aoVal": "C", "content": "$$60$$ " } ], [ { "aoVal": "D", "content": "$$90$$ " } ], [ { "aoVal": "E", "content": "$$120$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions" ]
[ "$\\dfrac{1}{4}$kangyear x~$\\dfrac{20\\textbackslash{} kangmonths}{1\\textbackslash{} kangyear}$~x~$\\dfrac{6\\textbackslash{} kangweeks}{1\\textbackslash{} kangmonth}$~= 30 kangweeks. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3256
2f8118d645384ada90ffe775e12e9d20
[ "其它" ]
1
single_choice
A vase was being sold at the price of $250$ dollars. The store decides to sell it with a $40\textbackslash\%$ discount. If you buy the vase now, how much will you save?
[ [ { "aoVal": "A", "content": "$$150$$ " } ], [ { "aoVal": "B", "content": "$$100$$ " } ], [ { "aoVal": "C", "content": "$$80$$ " } ], [ { "aoVal": "D", "content": "$$50$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Percentage Calculation" ]
[ "$250\\times 40\\textbackslash\\%$ " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3262
58d3c74b24664a3cb0fc82356cb97f24
[ "其它" ]
1
single_choice
Calculate: $$2.7\times0.2\div3=$$.
[ [ { "aoVal": "A", "content": "$0.16$ " } ], [ { "aoVal": "B", "content": "$1.6$ " } ], [ { "aoVal": "C", "content": "$0.18$ " } ], [ { "aoVal": "D", "content": "$1.8$ " } ], [ { "aoVal": "E", "content": "$0.14$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Decimals->Multiplication and Division of Decimals" ]
[ "$$2.7\\times0.2\\div3$$ $$=0.54\\div3$$ $$=0.18$$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3264
21fded3a3d774d508f7ba65bcfc03795
[ "其它" ]
1
single_choice
Mary wanted to buy $12$ lemons. The lemons were sold either for $90$ cents each or at $3$ dollars for a bag of $4$ lemons. How much money would Mary save if she buys three bags of lemons instead of buying $12$ lemons separately?
[ [ { "aoVal": "A", "content": "$1.2$ dollars " } ], [ { "aoVal": "B", "content": "$1.5$ dollars " } ], [ { "aoVal": "C", "content": "$1.6$ dollars " } ], [ { "aoVal": "D", "content": "$1.8$ dollars " } ], [ { "aoVal": "E", "content": "$2.1$ dollars " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "$0.9 \\times 12 - 3 \\times 3 = 1.8$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3269
4b057a81ece5453cbc863a9390e2a87d
[ "其它" ]
1
single_choice
The following are the weights (in pounds) of ten people: $100,115, 135, 140, 180, 197, 203, 230, x, y$ (not necessarily in increasing order). It is also given that the average weight of these ten people is $157$ pounds, and there is a unique mode of $135$. Find the $56$-th percentile.
[ [ { "aoVal": "A", "content": "$$100$$ " } ], [ { "aoVal": "B", "content": "$$115$$ " } ], [ { "aoVal": "C", "content": "$$125$$ " } ], [ { "aoVal": "D", "content": "$$135$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "First of all, we find the values of $x$ and $y$. Since the average is $157$, we have $(100+115+135+140+ 180+197+203+230+x+y = 157 \\times 10 = 1570$ $1300+x+y =1570$ $x+y = 270$. There is a unique mode, $135$, then $135$ must appear at least twice. Therefore, one of $x, y$ is $135$. It is easy to deduce that both $x$ and $y$ are $135$. List the weights in increasing order: $100,115, 135, 135, 135, 140, 180, 197, 203, 230$. $np=10(0.56)=5.6 \\uparrow 6$. The $56$-th percentile is $140$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3270
19497aea1f704de08090350deae1c33b
[ "其它" ]
1
single_choice
Which of the following equations are NOT equivalent to $x+5=13$?
[ [ { "aoVal": "A", "content": "$x+5-5=13-5$ " } ], [ { "aoVal": "B", "content": "$2(x+5)=26$ " } ], [ { "aoVal": "C", "content": "$x+5-13=0$ " } ], [ { "aoVal": "D", "content": "$x+5+13=0$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation" ]
[ "Equations are equivalent when you can obtain one by subtracting, adding, dividing, or multiplying the same number on the other. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3274
341a7691f2514dbc8fc63d2f3460b378
[]
1
single_choice
$$\frac{1}{9}+ \frac{3}{9}+ \frac{5}{9}=$$.
[ [ { "aoVal": "A", "content": "$$\\frac{1}{3}$$ " } ], [ { "aoVal": "B", "content": "$$1$$ " } ], [ { "aoVal": "C", "content": "$$\\frac{10}{9}$$ " } ], [ { "aoVal": "D", "content": "$$\\frac{5}{243}$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Operations of Fractions" ]
[ "$$\\frac{1}{9}+ \\frac{3}{9}+ \\frac{5}{9}= \\frac{9}{9}=1$$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3277
194ee6d931274284a25e5690ee08b9ce
[ "其它" ]
0
single_choice
What is $$9762 + 7 \times 8 \times 9 \times 4 \times 99 \times 0$$
[ [ { "aoVal": "A", "content": "$$9762$$ " } ], [ { "aoVal": "B", "content": "$$9818$$ " } ], [ { "aoVal": "C", "content": "$$9889$$ " } ], [ { "aoVal": "D", "content": "$$209346$$ " } ], [ { "aoVal": "E", "content": "None of the above " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "Anything times $$0$$ equal $$0$$. $$9762 + 0 = 9762$$ " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3278
38ae263839cd4d3eba1db18b241ce7c9
[ "其它" ]
2
single_choice
In a triangle with integer side lengths, one side is three times as long as a second side, and the length of the third side is $15$. What is the greatest possible perimeter of the triangle? (2006 AMC10B, Question 10)
[ [ { "aoVal": "A", "content": "$$43$$ " } ], [ { "aoVal": "B", "content": "$$44$$ " } ], [ { "aoVal": "C", "content": "$$45$$ " } ], [ { "aoVal": "D", "content": "$$46$$ " } ], [ { "aoVal": "E", "content": "$$47$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "Let $x$ be the length of the first side. The lengths of the sides are: $x, 3 x$, and 15 . By the Triangle Inequality, $$ \\begin{aligned} \\&3 x\\textless x+15 \\textbackslash\\textbackslash{} \\&2 x\\textless15 \\textbackslash\\textbackslash{} \\&x\\textless\\frac{15}{2} \\end{aligned} $$ The greatest integer satisfying this inequality is 7 . So the greatest possible perimeter is $7+3 \\cdot 7+15=$ (A) 43 " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3281
794303f54c514be1ada033886d8e62ee
[]
1
single_choice
$$1 + 10 + 100 + 1000 =$$.
[ [ { "aoVal": "A", "content": "$$4$$ " } ], [ { "aoVal": "B", "content": "$$1111$$ " } ], [ { "aoVal": "C", "content": "$$1234$$ " } ], [ { "aoVal": "D", "content": "$$4000$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Addition and Subtraction " ]
[ "$$1 + 10 + 100 + 1000 =11+11$$ hundred $$=1111$$. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3282
98d26ede6f794ef48df034f32c552962
[]
1
single_choice
The $$2022$$th digit to the right of the decimal point in the decimal representation of $$\frac 1{54}$$ is.
[ [ { "aoVal": "A", "content": "$$0$$ " } ], [ { "aoVal": "B", "content": "$$1$$ " } ], [ { "aoVal": "C", "content": "$$5$$ " } ], [ { "aoVal": "D", "content": "$$8$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Word Problem Modules->Periodic Problems->Periodic Problems of Sequence Operations" ]
[ "The decimal is $$0.0185185\\cdots $$. An \"$$8$$\" appears in the $$3$$rd, $$6$$th, $$9$$th, $$\\cdots $$, $$2022$$th decimal place. So a \"$$8$$\" is in the $$2022$$th place. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3283
41dda41f37a54ceeade78881ad9a241f
[]
1
single_choice
According to the regulation of the pyramid series, the formula $$1+2+3+4+5+6+5+4+3+2+1=$$.
[ [ { "aoVal": "A", "content": "$$6\\times6$$ " } ], [ { "aoVal": "B", "content": "$$6\\times7$$ " } ], [ { "aoVal": "C", "content": "$$6\\times5$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables" ]
[ "``Pyramid series''$$1+2+3+4+\\cdots +\\left( n-1 \\right)+n+\\left( n-1 \\right)+\\cdots +3+2+1$$ $$={{n}^{2}}$$. So the answer is $$\\text{A}$$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3286
268bea9cb73a4149a8d99051ca743043
[]
0
single_choice
Which of the following has a result of $183$?
[ [ { "aoVal": "A", "content": "$$103+86$$ " } ], [ { "aoVal": "B", "content": "$$117+76$$ " } ], [ { "aoVal": "C", "content": "$$90+83$$ " } ], [ { "aoVal": "D", "content": "$$82+101$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Addition and Subtraction " ]
[ "$$103+86=189$$ $$117+76=193$$ $$90+83=173$$ $$82+101=183$$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3287
268cdc9de32f4468b6c377df36dc9679
[]
1
single_choice
Calculate: $$\frac{1}{4}\times \frac{5}{6}+\frac{3}{7}\times \frac{7}{8}=$$.
[ [ { "aoVal": "A", "content": "$$\\frac{5}{12}$$ " } ], [ { "aoVal": "B", "content": "$$\\frac{5}{16}$$ " } ], [ { "aoVal": "C", "content": "$$\\frac{5}{17}$$ " } ], [ { "aoVal": "D", "content": "$$\\frac{7}{12}$$ " } ], [ { "aoVal": "E", "content": "$$\\frac{11}{12}$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Operations of Fractions" ]
[ "$$\\frac{1}{4}\\times \\frac{5}{6}+\\frac{3}{7}\\times \\frac{7}{8}$$=$$\\frac{5}{24}+\\frac{3}{8}$$=$$\\frac{5}{24}+\\frac{9}{24}$$=$$\\frac{14}{24}$$=$$\\frac{7}{12}$$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3294
1184c85e9c074d8d964671f585e4cc72
[]
1
single_choice
Simplify the following expression: $$a^{2}\times a+b^{2}\times b^{3}$$.
[ [ { "aoVal": "A", "content": "$$a^{3}+b^{5}$$ " } ], [ { "aoVal": "B", "content": "$$a^{3}b^{5}$$ " } ], [ { "aoVal": "C", "content": "$$a^{2}+b^{5}$$ " } ], [ { "aoVal": "D", "content": "$$a^{2}+b^{6}$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Power->Computing Powers" ]
[ "$$a^{2}\\times a+b^{2}\\times b^{3}=$$$$a^{3}+b^{5}$$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3297
2b0d61123980438fa2a96e1bcae6c2af
[]
1
single_choice
What is the next number in this sequence? $$1$$, $$2$$, $$3$$, $$6$$, $$11$$, $$20$$, $$37$$,~\uline{~~~~~~~~~~}~? .
[ [ { "aoVal": "A", "content": "$$47$$ " } ], [ { "aoVal": "B", "content": "$$54$$ " } ], [ { "aoVal": "C", "content": "$$57$$ " } ], [ { "aoVal": "D", "content": "$$68$$ " } ], [ { "aoVal": "E", "content": "$$74$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Patterns in Number Sequences" ]
[ "After the first three numbers, each number is the sum of the previous three numbers. So the next number is $$11 + 20 + 37 = 68$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3302
1db905558a66450a8a1e6b387136a2f6
[ "其它" ]
2
single_choice
\textbf{Sean and Evan are college roommates who have part-time jobs as servers in restaurants. The distribution of Sean's weekly income is approximately normal with mean $\textbackslash$225$ and standard deviation $\textbackslash$25$. The distribution of Evan's weekly income is approximately normal with mean $\textbackslash$240$ and standard deviation $15. Assuming their weekly incomes are independent of each other, which of the following is closest to the probability that Sean will have a greater income than Evan in a randomly selected week?}
[ [ { "aoVal": "A", "content": "\\textbf{0.067} " } ], [ { "aoVal": "B", "content": "\\textbf{0.159} " } ], [ { "aoVal": "C", "content": "\\textbf{0.227} " } ], [ { "aoVal": "D", "content": "\\textbf{0.303} " } ], [ { "aoVal": "E", "content": "\\textbf{0.354} " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "\\textbf{Sean \\textasciitilde{} N(225, 25)} \\textbf{Evan \\textasciitilde{} N(240, 15)} \\textbf{→} \\textbf{Sean - Evan \\textasciitilde{} N(-15, 29.155)} \\textbf{P(Sean-Evan \\textgreater{} 0) = 1-P(X\\textless0) = 0.303} " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3304
221fbe122a08482c918036dd259c03af
[ "其它" ]
1
single_choice
An amusement park has a collection of scale models, with ratio $1: 40$, of buildings and other sights from around the country. The height of empire state building is 1250 feet. What is the height in feet of its replica to the nearest whole number? (adapted from 2018 AMC 8, Question 1)
[ [ { "aoVal": "A", "content": "$$30$$ " } ], [ { "aoVal": "B", "content": "$$31$$ " } ], [ { "aoVal": "C", "content": "$$32$$ " } ], [ { "aoVal": "D", "content": "$$33$$ " } ], [ { "aoVal": "E", "content": "$$34$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions" ]
[ "You can see that since the ratio of real building\\textquotesingle s heights to the model building\\textquotesingle s height is $1: 40$. We also know that the Empire State Building is 1250 feet, so to find the height of the model, we divide by 40 . That gives us $31.25$ which rounds to 31 . Therefore, to the nearest whole number, the duplicate is (B) 31 feet. " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3308
cbdfd117a28345e39ef4c31a6f120e4c
[ "其它" ]
1
single_choice
A basketball is on sale with 35\% off, the discounted price is $$52$$ dollars, the original price of the basketball wasdollars.
[ [ { "aoVal": "A", "content": "$$18.2$$ " } ], [ { "aoVal": "B", "content": "$$33.8$$ " } ], [ { "aoVal": "C", "content": "$$80$$ " } ], [ { "aoVal": "D", "content": "$$148$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "$$x \\times 65\\textbackslash\\% = 52$$ $$x = 80$$ " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3312
544b34950e3f413d94bfff58e2a2d61c
[]
1
single_choice
Which of these is equal to $$(0.3+0.4 + 0.5 -0.9)\div0.6$$?
[ [ { "aoVal": "A", "content": "$$0.02 $$ " } ], [ { "aoVal": "B", "content": "$$0.05 $$ " } ], [ { "aoVal": "C", "content": "$$0.2 $$ " } ], [ { "aoVal": "D", "content": "$$0.5$$ " } ], [ { "aoVal": "E", "content": "$$1$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Decimals->Four Operations of Decimals" ]
[ "Note that $$(0.3+0.4+0.5 -0.9)\\div0.6 =(1.2 -0.9)\\div0.6 =0.3\\div0.6 = 3\\div6$$ $$=0.5$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3318
38c53be9572f4affbdbb72551ff8c50b
[ "其它" ]
0
single_choice
The ratio of $w$ to $x$ is $4: 3$, the ratio of $y$ to $z$ is $3: 2$, and the ratio of $z$ to $x$ is $1: 6$. What is the ratio of $w$ to $y$? (2020 AMC 10B Problems, Question \#3)
[ [ { "aoVal": "A", "content": "$4: 3$ " } ], [ { "aoVal": "B", "content": "$3: 2$ " } ], [ { "aoVal": "C", "content": "$8: 3$ " } ], [ { "aoVal": "D", "content": "$4: 1$ " } ], [ { "aoVal": "E", "content": "$16: 3$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "We need to somehow link all three of the ratios together. We can start by connecting the last two ratios together by multiplying the last ratio by two. $z: x=1: 6=2: 12$, and since $y: z=3: 2$, we can link them together to get $y: z: x=3: 2: 12$. Finally, since $x: w=3: 4=12: 16$, we can link this again to get: $y: z: x: w=3: 2: 12: 16$, so $w: y=(\\mathbf{E}) 16: 3$. " ]
E
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3323
11bf02814ab34c17909f045cd43a5820
[ "其它" ]
0
single_choice
The digit $9$ in what number represents a value of $0.09$?
[ [ { "aoVal": "A", "content": "$$9.012$$ " } ], [ { "aoVal": "B", "content": "$$0.469$$ " } ], [ { "aoVal": "C", "content": "$$51.9$$ " } ], [ { "aoVal": "D", "content": "$$26.49$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Decimals->Basic Understanding of Decimals" ]
[ "If the digit $$9$$ represents a value of $$0.09$$, it means the digit $$9$$ is located on the hundredth place on that number, which is the second digit after the decimal point. Check Lesson 4 Concept 1 on textbook " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3334
8f9727d2e34943bbb7756e11519a210b
[ "其它" ]
2
single_choice
What is the smallest whole number larger than the perimeter of any triangle with a side of length $9$ and a side of length $1$? (adapted from 2015 AMC8, Question 8)
[ [ { "aoVal": "A", "content": "$$10$$ " } ], [ { "aoVal": "B", "content": "$$19$$ " } ], [ { "aoVal": "C", "content": "$$20$$ " } ], [ { "aoVal": "D", "content": "$$21$$ " } ], [ { "aoVal": "E", "content": "$$22$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Inequalities" ]
[ "We know from the triangle inequality that the last side, $s$, fulfills $s\\textless9+1=10$. Adding $9+1$ to both sides of the inequality, we get $s+9+1\\textless20$, and because $s+9+1$ is the perimeter of our triangle, (C) 20 is our answer. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3340
4fb752545a624cc9b34f7ad4d607355c
[ "其它" ]
1
single_choice
The sum of three numbers is $20$. The first is four times the sum of the other two. The second is seven times the third. What is the product of all three numbers?
[ [ { "aoVal": "A", "content": "$$18$$ " } ], [ { "aoVal": "B", "content": "$$28$$ " } ], [ { "aoVal": "C", "content": "$$32$$ " } ], [ { "aoVal": "D", "content": "$$40$$ " } ], [ { "aoVal": "E", "content": "$$294$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "B " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3345
11daa872b99c46b4831afd0b857a18ec
[]
1
single_choice
$$4\times4\times20\times20=80\times$$?
[ [ { "aoVal": "A", "content": "$$80$$ " } ], [ { "aoVal": "B", "content": "$$20$$ " } ], [ { "aoVal": "C", "content": "$$4$$ " } ], [ { "aoVal": "D", "content": "$$2$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "$$(4\\times20)\\times (4\\times20)=80\\times80$$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3349
19a2c6e824074bf4a232d87d48cff7ef
[ "其它" ]
1
single_choice
The number $-11+(-7)$ is equal to:
[ [ { "aoVal": "A", "content": "$$3$$ " } ], [ { "aoVal": "B", "content": "$$-3$$ " } ], [ { "aoVal": "C", "content": "$$-25$$ " } ], [ { "aoVal": "D", "content": "$$25$$ " } ], [ { "aoVal": "E", "content": "$$-18$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Mixed Operations" ]
[ "$-11+(-7)=-18$. " ]
E
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3360
94426feb080e432c82996da41b2b1b95
[]
1
single_choice
If $$2x-3=y+5$$ and $$3y-1=5$$, then $$x=$$.
[ [ { "aoVal": "A", "content": "$$3$$ " } ], [ { "aoVal": "B", "content": "$$4$$ " } ], [ { "aoVal": "C", "content": "$$5$$ " } ], [ { "aoVal": "D", "content": "$$7$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Equivalent Substitution->Algebraic Expressions" ]
[ "From $$3y -1=5$$, then we can get $$y=2$$. Therefore from $$2x-3=2+5$$, we obtain $$x=5$$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3363
224d543d02ad48dfa35f1086aaa2c7ea
[ "其它" ]
2
single_choice
Write each of the numbers 0,1,2,3,4,5,6 in the sqaures to make the addition correct. What digit will be in the grey square? pic
[ [ { "aoVal": "A", "content": "$$2$$ " } ], [ { "aoVal": "B", "content": "$$3$$ " } ], [ { "aoVal": "C", "content": "$$4$$ " } ], [ { "aoVal": "D", "content": "$$5$$ " } ], [ { "aoVal": "E", "content": "$$6$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Operations with New Definition->Finding Patterns->Encryption and Decryption" ]
[ "work backwards " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3370
344e2d2e73d348daaee93e69c4cce343
[]
1
single_choice
What is the product of $125$ and $6$?
[ [ { "aoVal": "A", "content": "$$420$$ " } ], [ { "aoVal": "B", "content": "$$1230$$ " } ], [ { "aoVal": "C", "content": "$$750$$ " } ], [ { "aoVal": "D", "content": "$$720$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Multiplication and Division" ]
[ "omitted " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3372
12030463e2a04760912a8fbfc9d07f67
[ "其它" ]
1
single_choice
If 5 plates weigh as much as 9 mugs, then 99 mugs weigh as much as~\uline{~~~~~~~~~~}~plates.
[ [ { "aoVal": "A", "content": "$$10$$ " } ], [ { "aoVal": "B", "content": "$$18$$ " } ], [ { "aoVal": "C", "content": "$$55$$ " } ], [ { "aoVal": "D", "content": "$$50$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Basic Concepts of Equation->Equivalent Substitution" ]
[ "omitted " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3391
6b74c4d6297543859672b09a9aea3b98
[ "其它" ]
2
single_choice
On the first day of a $7-$day holiday, Judy reads $9$ pages of a book. On the second day, she reads $12$. Then each day later, she reads $3$ pages more than the day before. On the last day of the holiday, she reads the corresponding number of pages and exactly finishes reading the book. How many pages does the book have?
[ [ { "aoVal": "A", "content": "$$27$$ " } ], [ { "aoVal": "B", "content": "$$30$$ " } ], [ { "aoVal": "C", "content": "$$120$$ " } ], [ { "aoVal": "D", "content": "$$126$$ " } ], [ { "aoVal": "E", "content": "$$128$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Arithmetic Sequences" ]
[ "Use the formula of arithmetic sequence to solve this problem. On the last day, she reads $9+6\\times3=27$ pages. The book has $(9+27)\\times7 \\div2=126$ pages. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3393
6b764442083a424f901b4e879b668396
[]
1
single_choice
Linda, Alice, Joe, Lily, and Rachel lost their balloons. The numbers on their balloons were all smaller than $8$. The difference between the largest number and the smallest number was $5$. What are their balloon\textquotesingle s numbers? (adapted from $$2021$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$8$$)
[ [ { "aoVal": "A", "content": "$7, 5, 4, 3,2$ " } ], [ { "aoVal": "B", "content": "$4, 1, 7,9,6$ " } ], [ { "aoVal": "C", "content": "$6,4,2,5,3$ " } ], [ { "aoVal": "D", "content": "$0,7,4,9,5$ " } ], [ { "aoVal": "E", "content": "$1,8,5,4,6$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Addition and Subtraction ->Subtraction of Whole Numbers->Subtraction in Horizontal Form" ]
[ "In~ B, D, and E, the largest number more than $8$. In the C, the difference between the largest number and the smallest number is $4$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3394
cbe7c5cf77d045cc877c080e41decd05
[ "其它" ]
1
single_choice
$$8+9+12+17+23+31=$$?.
[ [ { "aoVal": "A", "content": "$$100$$ " } ], [ { "aoVal": "B", "content": "$$90$$ " } ], [ { "aoVal": "C", "content": "$$80$$ " } ], [ { "aoVal": "D", "content": "$$70$$ " } ], [ { "aoVal": "E", "content": "$$50$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Whole Numbers Addition and Subtraction ->Addition of Whole Numbers" ]
[ "$$=8+12+9+31+23+17$$ $$=20+40+40$$ $$=100$$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3402
4b33a4397d3e419db68d0ae52b802da2
[]
1
single_choice
$$$$Calculate$$$$ $$\left (403 \frac{3}{5}+183 \frac{5}{11}+155 \frac{3}{13}+118 \frac{12}{17}\right ) \div$$$$ \left~~( \frac{1009}{15}+ \frac{1009}{33}+ \frac{1009}{39}+ \frac{1009}{51}\right )$$.
[ [ { "aoVal": "A", "content": "$$5$$ " } ], [ { "aoVal": "B", "content": "$$5.5$$ " } ], [ { "aoVal": "C", "content": "$$6$$ " } ], [ { "aoVal": "D", "content": "$$6.5$$ " } ], [ { "aoVal": "E", "content": "None of the above " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Fast Calculation in Fractions" ]
[ "$$\\left (403 \\frac{3}{5}+183 \\frac{5}{11}+155 \\frac{3}{13}+118 \\frac{12}{17}\\right ) \\div$$$$ \\left ( \\frac{1009}{15}+ \\frac{1009}{33}+ \\frac{10009}{39}+ \\frac{1009}{51}\\right )$$ $$=2018\\left ( \\frac{1}{5}+ \\frac{1}{11}+ \\frac{1}{13}+ \\frac{1}{17}\\right ) \\div \\frac{1000}{3}\\left ( \\frac{1}{5}+ \\frac{1}{11}+ \\frac{1}{13}+ \\frac{1}{17}\\right )$$ $=6$. " ]
C
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3405
3d76d99232d14dd2aee1be5b933e1c4b
[ "其它" ]
0
single_choice
What is the next number in the sequence below? $$47, 44, 38, 29, 17, \cdots $$
[ [ { "aoVal": "A", "content": "$$12$$ " } ], [ { "aoVal": "B", "content": "$$8$$ " } ], [ { "aoVal": "C", "content": "$$5$$ " } ], [ { "aoVal": "D", "content": "$$2$$ " } ], [ { "aoVal": "E", "content": "None of the above " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Patterns in Number Sequences" ]
[ "The pattern is: $$-3, -6, -9, -12, -15, \\cdots $$ Thus, $$17-15=2$$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3413
19ddc6e443b74cf08a1a69d4cbd68974
[ "其它" ]
1
single_choice
$10000$ years ago, Owen the fisher traded $3$ fishes for $1$ rabbit from Oscar the hunter. Then, Oscar traded $2$ rabbits for $3$ packs of wheat from Dennis the farmer. How many fishes should Owen give Dennis for a pack of wheat?
[ [ { "aoVal": "A", "content": "$$1$$ " } ], [ { "aoVal": "B", "content": "$$2$$ " } ], [ { "aoVal": "C", "content": "$$3$$ " } ], [ { "aoVal": "D", "content": "$$4$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions->Proportions->Simplifying Continued Ratios" ]
[ "fish:rabbit$=3:1$ wheat:rabbit$=3:2$ fish: wheat$=2:1$ " ]
B
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3416
1e1825c7a3b146368f107f216fb7bc8a
[ "其它" ]
1
single_choice
Harry and Terry are each told to calculate $8-(2+5)$.~Harry gets the correct answer. Terry ignores the parentheses and calculates $8-2+5$.~If Harry\textquotesingle s answer is $H$~and Terry\textquotesingle s answer is $T$, what is $H-T$? (2014 AMC $8$ Problem, Question \#1)
[ [ { "aoVal": "A", "content": "$$-10$$ " } ], [ { "aoVal": "B", "content": "$$-6$$ " } ], [ { "aoVal": "C", "content": "$$0$$ " } ], [ { "aoVal": "D", "content": "$$6$$ " } ], [ { "aoVal": "E", "content": "$$10$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Mixed Operations" ]
[ "We have $H=8-7=1$ and $T=8-2+5=11$. Clearly $1-11=-10$, so our answer is $A$. " ]
A
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3418
58fcf59618bf4aa8ac9626033ac19e96
[ "其它" ]
1
single_choice
Two non-zero real numbers, $x$ and $y$, satisfy $(x+y)^{2}=3xy$. Which of the following is a possible value of $$\frac{x+y}{y}-\frac{x-y}{x}$$? (Adapted From 2000 AMC 12 Problems, Question \#11)
[ [ { "aoVal": "A", "content": "$-1$ " } ], [ { "aoVal": "B", "content": "$-\\frac{1}{2}$ " } ], [ { "aoVal": "C", "content": "$\\frac{1}{2}$ " } ], [ { "aoVal": "D", "content": "$1$ " } ], [ { "aoVal": "E", "content": "$$2$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules" ]
[ "Note that $(x+y)^{2} = x^{2}+y^{2}+2xy = 3xy \\Rightarrow x^{2}+y^{2} = xy$. Then, $$\\frac{x+y}{y}-\\frac{x-y}{x}=\\frac{x(x+y)-y(x-y)}{xy}=\\frac{{{x}^{2}}+xy-xy+{{y}^{2}}}{xy}=\\frac{{{x}^{2}}+{{y}^{2}}}{xy} = 1$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3419
123e1c6a9ce048e682373cdfdf18e259
[ "其它" ]
0
single_choice
Eddie has a card. The number on the card is a neighbouring number of 8, but is not a neighbouring number of 6. What is the number on Eddie\textquotesingle s card?~\uline{~~~~~~~~~~}~
[ [ { "aoVal": "A", "content": "$$6$$ " } ], [ { "aoVal": "B", "content": "$$7$$ " } ], [ { "aoVal": "C", "content": "$$8$$ " } ], [ { "aoVal": "D", "content": "$$9$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers" ]
[ "$$Omitted.$$ " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3420
b4b7aa1d17ed41b78291b053e664475b
[]
1
single_choice
What percent of $$20$$ is $$50$$?
[ [ { "aoVal": "A", "content": "$$40$$ " } ], [ { "aoVal": "B", "content": "$$140$$ " } ], [ { "aoVal": "C", "content": "$$200$$ " } ], [ { "aoVal": "D", "content": "$$250$$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Fractions->Basic Understanding of Fractions" ]
[ "$$\\frac{50}{20}=2.5=2.5\\times100\\textbackslash\\%=250\\textbackslash\\%$$. " ]
D
prime_math_competition_en_single_choice_8K_dev
2023-07-07T00:00:00
3423
46a1f7bb3e2d4fa0a5b14a723092a395
[ "其它" ]
1
single_choice
If $A:B=3:5$, $B:C=3:2$, find $A:B:C$.
[ [ { "aoVal": "A", "content": "$3:5:4$ " } ], [ { "aoVal": "B", "content": "$9:15:10$ " } ], [ { "aoVal": "C", "content": "$9:3:10$ " } ], [ { "aoVal": "D", "content": "$8:15:10$ " } ] ]
[ "Overseas Competition->Knowledge Point->Calculation Modules->Ratios and Proportions" ]
[ "$A:B=3:5$ $B:C=3:2$ $A:B:C=9:15:10$ " ]
B