Unnamed: 0
int64
0
40.3k
problem
stringlengths
10
5.15k
ground_truth
stringlengths
1
1.22k
solved_percentage
float64
0
100
28,100
Xiao Zhang and Xiao Zhao can only take on the first two roles, while the other three can take on any of the four roles, calculate the total number of different selection schemes.
48
3.90625
28,101
There are 10 cards, labeled from 1 to 10. Three cards denoted by $ a,\ b,\ c\ (a > b > c)$ are drawn from the cards at the same time. Find the probability such that $ \int_0^a (x^2 \minus{} 2bx \plus{} 3c)\ dx \equal{} 0$ .
1/30
8.59375
28,102
In △ABC, the sides opposite to angles A, B, C are a, b, c, respectively. Given cosB= $\frac {2}{5}$, and sinAcosB - (2c - cosA)•sinB = 0. (1) Find the value of b; (2) Find the maximum value of the perimeter of △ABC.
\frac { \sqrt {30}}{6} + \frac {1}{2}
0
28,103
What is the smallest positive value of $x$ such that $x + 3956$ results in a palindrome?
48
0.78125
28,104
Mindy is attempting to solve the quadratic equation by completing the square: $$100x^2+80x-144 = 0.$$ She rewrites the given quadratic equation in the form $$(dx + e)^2 = f,$$ where \(d\), \(e\), and \(f\) are integers and \(d > 0\). What are the values of \(d + e + f\)?
174
17.96875
28,105
On a grid, there are three locations $A, B, C$, with each small square having a side length of 100 meters. If roads are to be built along the grid lines to connect the three locations, what is the minimum total length of the roads in meters?
1000
3.125
28,106
Given that children enter at a discounted rate, half that of an adult ticket, and the total cost for $6$ adult tickets and $5$ child tickets amounts to $32.50$, calculate the total cost for $10$ adult tickets and $8$ child tickets.
53.50
0
28,107
In the equation $\frac{1}{(\;\;\;)} + \frac{4}{(\;\;\;)} + \frac{9}{(\;\;\;\;)} = 1$, fill in the three brackets in the denominators with a positive integer, respectively, such that the equation holds true. The minimum value of the sum of these three positive integers is $\_\_\_\_\_\_$.
36
36.71875
28,108
The sequence $\{a_n\}$ satisfies $a_{n+1} + (-1)^n a_n = 2n - 1$. Find the sum of the first 60 terms of $\{a_n\}$.
1830
25
28,109
In a plane Cartesian coordinate system, a point whose x and y coordinates are both integers is called a "lattice point." How many lattice points are there inside and on the boundaries of the triangle formed by the line $7x + 11y = 77$ and the coordinate axes?
49
8.59375
28,110
In the Cartesian coordinate system, A and B are points moving on the x-axis and y-axis, respectively. If the circle C with AB as its diameter is tangent to the line $3x+y-4=0$, then the minimum area of circle C is \_\_\_\_\_\_.
\frac {2}{5}\pi
0
28,111
Find the smallest positive integer $n$ for which $315^2-n^2$ evenly divides $315^3-n^3$ . *Proposed by Kyle Lee*
90
50
28,112
In the polar coordinate system, the curve $\rho=4\sin \left( \theta- \frac{\pi}{3} \right)$ is symmetric about what axis?
\frac{5\pi}{6}
0
28,113
If \[1 \cdot 1992 + 2 \cdot 1991 + 3 \cdot 1990 + \dots + 1991 \cdot 2 + 1992 \cdot 1 = 1992 \cdot 996 \cdot y,\] compute the integer \(y\).
664
3.125
28,114
Let $k$ be a real number such that the product of real roots of the equation $$ X^4 + 2X^3 + (2 + 2k)X^2 + (1 + 2k)X + 2k = 0 $$ is $-2013$ . Find the sum of the squares of these real roots.
4027
4.6875
28,115
Given functions \(f(x)\) and \(g(x)\) are defined on \(\mathbb{R}\) with \(g(x)\neq 0\), and \(f(x)g'(x) > f'(x)g(x)\). It is also given that \(f(x)=a^{x}\cdot g(x)\) where \(a > 0, a\neq 1\), and \(\frac{f(1)}{g(1)} + \frac{f(-1)}{g(-1)} = \frac{5}{2}\). Considering the finite sequence \(\left\{\frac{f(n)}{g(n)}\right\}_{n=1,2,\ldots,10}\), find the probability that the sum of the first \(k\) terms is greater than \(\frac{15}{16}\) for any positive integer \(k\) with \(1 \leq k \leq 10\).
\frac{3}{5}
31.25
28,116
Given that $k$ is a composite number, and $1 < k < 100$, when the sum of the digits of $k$ is a prime number, this prime number is called the "derived prime" of $k$. (1) If the "derived prime" of $k$ is 2, then $k=$ (2) Let set $A=\{P(k) | P(k)$ is the "derived prime" of $k\}$, $B=\{k | P(k)$ is the "derived prime" of $k\}$, then the number of elements in the set $A \cup B$ is
30
6.25
28,117
The following diagram shows equilateral triangle $\vartriangle ABC$ and three other triangles congruent to it. The other three triangles are obtained by sliding copies of $\vartriangle ABC$ a distance $\frac18 AB$ along a side of $\vartriangle ABC$ in the directions from $A$ to $B$ , from $B$ to $C$ , and from $C$ to $A$ . The shaded region inside all four of the triangles has area $300$ . Find the area of $\vartriangle ABC$ . ![Image](https://cdn.artofproblemsolving.com/attachments/3/a/8d724563c7411547d3161076015b247e882122.png)
768
4.6875
28,118
How many three-eighths are there in $8\frac{5}{3} - 3$?
17\frac{7}{9}
14.0625
28,119
Given vectors $\overrightarrow{a}=(2\cos\omega x,-2)$ and $\overrightarrow{b}=(\sqrt{3}\sin\omega x+\cos\omega x,1)$, where $\omega\ \ \gt 0$, and the function $f(x)=\overrightarrow{a}\cdot\overrightarrow{b}+1$. The distance between two adjacent symmetric centers of the graph of $f(x)$ is $\frac{\pi}{2}$. $(1)$ Find $\omega$; $(2)$ Given $a$, $b$, $c$ are the opposite sides of the three internal angles $A$, $B$, $C$ of scalene triangle $\triangle ABC$, and $f(A)=f(B)=\sqrt{3}$, $a=\sqrt{2}$, find the area of $\triangle ABC$.
\frac{3-\sqrt{3}}{4}
20.3125
28,120
The product of the digits of 4321 is 24. How many distinct four-digit positive integers are such that the product of their digits equals 18?
24
3.90625
28,121
Given a set $A_n = \{1, 2, 3, \ldots, n\}$, define a mapping $f: A_n \rightarrow A_n$ that satisfies the following conditions: ① For any $i, j \in A_n$ with $i \neq j$, $f(i) \neq f(j)$; ② For any $x \in A_n$, if the equation $x + f(x) = 7$ has $K$ pairs of solutions, then the mapping $f: A_n \rightarrow A_n$ is said to contain $K$ pairs of "good numbers." Determine the number of such mappings for $f: A_6 \rightarrow A_6$ that contain 3 pairs of good numbers.
40
57.03125
28,122
Given the ten digits 0, 1, 2, 3, …, 9 and the imaginary unit i, determine the total number of distinct imaginary numbers that can be formed.
90
2.34375
28,123
What is the smallest positive integer with exactly 12 positive integer divisors?
60
88.28125
28,124
A certain product in a shopping mall sells an average of 30 items per day, with a profit of 50 yuan per item. In order to reduce inventory quickly, the mall decides to take appropriate price reduction measures. After investigation, it was found that for each item, for every 1 yuan reduction in price, the mall can sell an additional 2 items per day. Let $x$ represent the price reduction per item. Based on this rule, please answer:<br/>$(1)$ The daily sales volume of the mall increases by ______ items, and the profit per item is ______ yuan (expressed in algebraic expressions containing $x$);<br/>$(2)$ Under the same conditions as above, in normal sales situations, how much should each item be reduced in price so that the mall's daily profit reaches 2100 yuan?
20
82.03125
28,125
Let $ a,b,c,d>0$ for which the following conditions:: $a)$ $(a-c)(b-d)=-4$ $b)$ $\frac{a+c}{2}\geq\frac{a^{2}+b^{2}+c^{2}+d^{2}}{a+b+c+d}$ Find the minimum of expression $a+c$
4\sqrt{2}
0.78125
28,126
There are 2 dimes of Chinese currency, how many ways can they be exchanged into coins (1 cent, 2 cents, and 5 cents)?
28
4.6875
28,127
Solve the equation: $2\left(x-1\right)^{2}=x-1$.
\frac{3}{2}
7.03125
28,128
What is the area of the portion of the circle defined by the equation $x^2 + 6x + y^2 = 50$ that lies below the $x$-axis and to the left of the line $y = x - 3$?
\frac{59\pi}{4}
4.6875
28,129
Let \( a_1, a_2, \ldots, a_{2020} \) be the roots of the polynomial \[ x^{2020} + x^{2019} + \cdots + x^2 + x - 2022 = 0. \] Compute \[ \sum_{n = 1}^{2020} \frac{1}{1 - a_n}. \]
2041210
2.34375
28,130
Amelia and Blaine are playing a modified game where they toss their respective coins. Amelia's coin lands on heads with a probability of $\frac{3}{7}$, and Blaine's lands on heads with a probability of $\frac{1}{3}$. They begin their game only after observing at least one head in a simultaneous toss of both coins. Once the game starts, they toss coins alternately with Amelia starting first, and the player to first toss heads twice consecutively wins the game. What is the probability that Amelia wins the game? A) $\frac{1}{2}$ B) $\frac{9}{49}$ C) $\frac{2401}{6875}$ D) $\frac{21609}{64328}$
\frac{21609}{64328}
10.9375
28,131
Seven cards numbered $1$ through $7$ are to be lined up in a row. Find the number of arrangements of these seven cards where one of the cards can be removed leaving the remaining six cards in either ascending or descending order.
10
0
28,132
In $\triangle ABC$, $AC=5 \sqrt {2}$, $\cos C= \frac {3}{5}$, $B= \frac {\pi}{4}$. (1) Find the length of $AB$; (2) Find the area of $\triangle ABC$, denoted as $S_{\triangle ABC}$.
28
75.78125
28,133
How many whole numbers between 1 and 2000 do not contain the digits 1 or 2?
511
3.90625
28,134
Given the function $f(x)=ax^{3}+2bx^{2}+3cx+4d$, where $a,b,c,d$ are real numbers, $a < 0$, and $c > 0$, is an odd function, and when $x\in[0,1]$, the range of $f(x)$ is $[0,1]$. Find the maximum value of $c$.
\frac{\sqrt{3}}{2}
0
28,135
In a large bag of decorative ribbons, $\frac{1}{4}$ are yellow, $\frac{1}{3}$ are purple, $\frac{1}{8}$ are orange, and the remaining 45 ribbons are silver. How many of the ribbons are orange?
19
21.09375
28,136
The water tank in the diagram below is in the shape of an inverted right circular cone. The radius of its base is 8 feet, and its height is 64 feet. The water in the tank is $40\%$ of the tank's capacity. The height of the water in the tank can be written in the form $a\sqrt[3]{b}$, where $a$ and $b$ are positive integers, and $b$ is not divisible by a perfect cube greater than 1. What is $a+b$?
66
2.34375
28,137
Ten circles of diameter 1 are arranged in the first quadrant of a coordinate plane. Five circles are in the base row with centers at $(0.5, 0.5)$, $(1.5, 0.5)$, $(2.5, 0.5)$, $(3.5, 0.5)$, $(4.5, 0.5)$, and the remaining five directly above the first row with centers at $(0.5, 1.5)$, $(1.5, 1.5)$, $(2.5, 1.5)$, $(3.5, 1.5)$, $(4.5, 1.5)$. Let region $\mathcal{S}$ be the union of these ten circular regions. Line $m,$ with slope $-2$, divides $\mathcal{S}$ into two regions of equal area. Line $m$'s equation can be expressed in the form $px=qy+r$, where $p, q,$ and $r$ are positive integers whose greatest common divisor is 1. Find $p^2+q^2+r^2$.
30
0.78125
28,138
Given the sequence $\{a\_n\}$, where $a\_1=1$, $a\_2=3$, and $2nS\_n=(n+1)S\_{n+1}+(n-1)S\_{n-1}$ ($n\geqslant 2,n\in N$), find $S\_{30}$.
\frac{34}{5}
0
28,139
Given an odd function defined on $\mathbb{R}$, when $x > 0$, $f(x)=x^{2}+2x-1$. (1) Find the value of $f(-3)$; (2) Find the analytic expression of the function $f(x)$.
-14
36.71875
28,140
Given $|m|=3$, $|n|=2$, and $m<n$, find the value of $m^2+mn+n^2$.
19
23.4375
28,141
In $\triangle ABC$, the sides opposite to angles A, B, and C are $a$, $b$, and $c$, respectively. Given the equation $$2b\cos A - \sqrt{3}c\cos A = \sqrt{3}a\cos C$$. (1) Find the value of angle A; (2) If $\angle B = \frac{\pi}{6}$, and the median $AM = \sqrt{7}$ on side $BC$, find the area of $\triangle ABC$.
\sqrt{3}
42.1875
28,142
In the diagram below, the circle with center $A$ is congruent to and tangent to the circle with center $B$ . A third circle is tangent to the circle with center $A$ at point $C$ and passes through point $B$ . Points $C$ , $A$ , and $B$ are collinear. The line segment $\overline{CDEFG}$ intersects the circles at the indicated points. Suppose that $DE = 6$ and $FG = 9$ . Find $AG$ . [asy] unitsize(5); pair A = (-9 sqrt(3), 0); pair B = (9 sqrt(3), 0); pair C = (-18 sqrt(3), 0); pair D = (-4 sqrt(3) / 3, 10 sqrt(6) / 3); pair E = (2 sqrt(3), 4 sqrt(6)); pair F = (7 sqrt(3), 5 sqrt(6)); pair G = (12 sqrt(3), 6 sqrt(6)); real r = 9sqrt(3); draw(circle(A, r)); draw(circle(B, r)); draw(circle((B + C) / 2, 3r / 2)); draw(C -- D); draw(" $6$ ", E -- D); draw(E -- F); draw(" $9$ ", F -- G); dot(A); dot(B); label(" $A$ ", A, plain.E); label(" $B$ ", B, plain.E); label(" $C$ ", C, W); label(" $D$ ", D, dir(160)); label(" $E$ ", E, S); label(" $F$ ", F, SSW); label(" $G$ ", G, N); [/asy]
9\sqrt{19}
0
28,143
The maximum value of the function $f(x) = \frac{\frac{1}{6} \cdot (-1)^{1+ C_{2x}^{x}} \cdot A_{x+2}^{5}}{1+ C_{3}^{2} + C_{4}^{2} + \ldots + C_{x-1}^{2}}$ ($x \in \mathbb{N}$) is ______.
-20
0.78125
28,144
Calculate the product of $1101_2 \cdot 111_2$. Express your answer in base 2.
1100111_2
0
28,145
Given an obtuse triangle \(ABC\) with obtuse angle \(C\). Points \(P\) and \(Q\) are marked on its sides \(AB\) and \(BC\) respectively, such that \(\angle ACP = CPQ = 90^\circ\). Find the length of segment \(PQ\) if it is known that \(AC = 25\), \(CP = 20\), and \(\angle APC = \angle A + \angle B\).
16
9.375
28,146
Given several numbers, one of them, $a$ , is chosen and replaced by the three numbers $\frac{a}{3}, \frac{a}{3}, \frac{a}{3}$ . This process is repeated with the new set of numbers, and so on. Originally, there are $1000$ ones, and we apply the process several times. A number $m$ is called *good* if there are $m$ or more numbers that are the same after each iteration, no matter how many or what operations are performed. Find the largest possible good number.
667
4.6875
28,147
Evaluate: $6 - 5\left[7 - (\sqrt{16} + 2)^2\right] \cdot 3.$
-429
33.59375
28,148
Solve the equations:<br/>$(1)x^{2}-4x-1=0$;<br/>$(2)\left(x+3\right)^{2}=x+3$.
-2
1.5625
28,149
Let $ABCD$ be a rectangle with side lengths $AB = CD = 5$ and $BC = AD = 10$ . $W, X, Y, Z$ are points on $AB, BC, CD$ and $DA$ respectively chosen in such a way that $WXYZ$ is a kite, where $\angle ZWX$ is a right angle. Given that $WX = WZ = \sqrt{13}$ and $XY = ZY$ , determine the length of $XY$ .
\sqrt{65}
2.34375
28,150
There are real numbers $a, b, c, d$ such that for all $(x, y)$ satisfying $6y^2 = 2x^3 + 3x^2 + x$ , if $x_1 = ax + b$ and $y_1 = cy + d$ , then $y_1^2 = x_1^3 - 36x_1$ . What is $a + b + c + d$ ?
90
39.84375
28,151
Given the function $f(x) = \frac{x}{\ln x}$, and $g(x) = f(x) - mx (m \in \mathbb{R})$, (I) Find the interval of monotonic decrease for function $f(x)$. (II) If function $g(x)$ is monotonically decreasing on the interval $(1, +\infty)$, find the range of the real number $m$. (III) If there exist $x_1, x_2 \in [e, e^2]$ such that $m \geq g(x_1) - g'(x_2)$ holds true, find the minimum value of the real number $m$.
\frac{1}{2} - \frac{1}{4e^2}
0
28,152
Define a positive integer $n$ to be a factorial tail if there is some positive integer $m$ such that the decimal representation of $m!$ ends with exactly $n$ zeroes. How many positive integers less than $2500$ are not factorial tails?
500
8.59375
28,153
A shepherd uses 15 segments of fencing, each 2 meters long, to form a square or rectangular sheep pen with one side against a wall. What is the maximum area of the sheep pen in square meters?
112
23.4375
28,154
It is planned to establish an additional channel for exchanging stereo audio signals (messages) for daily reporting communication sessions between two working sites of a deposit. Determine the required bandwidth of this channel in kilobits, considering that the sessions will be conducted for no more than 51 minutes. The requirements for a mono signal per second are given below: - Sampling rate: 63 Hz - Sampling depth: 17 bits - Metadata volume: 47 bytes for every 5 kilobits of audio
2.25
0
28,155
Let $A_1A_2A_3A_4A_5$ be a regular pentagon with side length 1. The sides of the pentagon are extended to form the 10-sided polygon shown in bold at right. Find the ratio of the area of quadrilateral $A_2A_5B_2B_5$ (shaded in the picture to the right) to the area of the entire 10-sided polygon. [asy] size(8cm); defaultpen(fontsize(10pt)); pair A_2=(-0.4382971011,5.15554989475), B_4=(-2.1182971011,-0.0149584477027), B_5=(-4.8365942022,8.3510997895), A_3=(0.6,8.3510997895), B_1=(2.28,13.521608132), A_4=(3.96,8.3510997895), B_2=(9.3965942022,8.3510997895), A_5=(4.9982971011,5.15554989475), B_3=(6.6782971011,-0.0149584477027), A_1=(2.28,3.18059144705); filldraw(A_2--A_5--B_2--B_5--cycle,rgb(.8,.8,.8)); draw(B_1--A_4^^A_4--B_2^^B_2--A_5^^A_5--B_3^^B_3--A_1^^A_1--B_4^^B_4--A_2^^A_2--B_5^^B_5--A_3^^A_3--B_1,linewidth(1.2)); draw(A_1--A_2--A_3--A_4--A_5--cycle); pair O = (A_1+A_2+A_3+A_4+A_5)/5; label(" $A_1$ ",A_1, 2dir(A_1-O)); label(" $A_2$ ",A_2, 2dir(A_2-O)); label(" $A_3$ ",A_3, 2dir(A_3-O)); label(" $A_4$ ",A_4, 2dir(A_4-O)); label(" $A_5$ ",A_5, 2dir(A_5-O)); label(" $B_1$ ",B_1, 2dir(B_1-O)); label(" $B_2$ ",B_2, 2dir(B_2-O)); label(" $B_3$ ",B_3, 2dir(B_3-O)); label(" $B_4$ ",B_4, 2dir(B_4-O)); label(" $B_5$ ",B_5, 2dir(B_5-O)); [/asy]
\frac{1}{2}
6.25
28,156
Given the polynomial $$Q(x) = \left(1 + x + x^2 + \ldots + x^{20}\right)^2 - x^{20},$$ find the sum $$\beta_1 + \beta_2 + \beta_6$$ where the complex zeros of $Q(x)$ are written in the form, $\beta_k=r_k[\cos(2\pi\beta_k)+i\sin(2\pi\beta_k)]$, with $0<\beta_1\le\beta_2\le\ldots\le\beta_{41}<1$ and $r_k>0$.
\frac{3}{7}
11.71875
28,157
Given the ellipse $C: \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 (a > b > 0)$ with its left and right foci being $F_1$ and $F_2$ respectively, and passing through the point $P(0, \sqrt{5})$, with an eccentricity of $\frac{2}{3}$, and $A$ being a moving point on the line $x=4$. - (I) Find the equation of the ellipse $C$; - (II) Point $B$ is on the ellipse $C$, satisfying $OA \perpendicular OB$, find the minimum length of segment $AB$.
\sqrt{21}
2.34375
28,158
A mathematical demonstration showed that there were distinct positive integers such that $97^4 + 84^4 + 27^4 + 3^4 = m^4$. Calculate the value of $m$.
108
1.5625
28,159
We denote by gcd (...) the greatest common divisor of the numbers in (...). (For example, gcd $(4, 6, 8)=2$ and gcd $(12, 15)=3$ .) Suppose that positive integers $a, b, c$ satisfy the following four conditions: $\bullet$ gcd $(a, b, c)=1$ , $\bullet$ gcd $(a, b + c)>1$ , $\bullet$ gcd $(b, c + a)>1$ , $\bullet$ gcd $(c, a + b)>1$ . a) Is it possible that $a + b + c = 2015$ ? b) Determine the minimum possible value that the sum $a+ b+ c$ can take.
30
51.5625
28,160
A rectangular piece of paper $A B C D$ is folded and flattened such that triangle $D C F$ falls onto triangle $D E F$, with vertex $E$ landing on side $A B$. Given that $\angle 1 = 22^{\circ}$, find $\angle 2$.
44
0
28,161
Given a triangle $\triangle ABC$ with its three interior angles $A$, $B$, and $C$ satisfying: $$A+C=2B, \frac {1}{\cos A}+ \frac {1}{\cos C}=- \frac { \sqrt {2}}{\cos B}$$, find the value of $$\cos \frac {A-C}{2}$$.
\frac { \sqrt {2}}{2}
0
28,162
What is the smallest positive integer with exactly 16 positive divisors?
384
0
28,163
A rectangular prism with dimensions 1 cm by 1 cm by 2 cm has a dot marked in the center of the top face (1 cm by 2 cm face). It is sitting on a table, which is 1 cm by 2 cm face. The prism is rolled over its shorter edge (1 cm edge) on the table, without slipping, and stops once the dot returns to the top. Find the length of the path followed by the dot in terms of $\pi$.
2\pi
50.78125
28,164
The height $BD$ of the acute-angled triangle $ABC$ intersects with its other heights at point $H$. Point $K$ lies on segment $AC$ such that the angle $BKH$ is maximized. Find $DK$ if $AD = 2$ and $DC = 3$.
\sqrt{6}
0.78125
28,165
On a luxurious ocean liner, 3000 adults consisting of men and women embark on a voyage. If 55% of the adults are men and 12% of the women as well as 15% of the men are wearing sunglasses, determine the total number of adults wearing sunglasses.
409
0
28,166
$2.46\times 8.163\times (5.17+4.829)$ is approximately equal to what value?
200
2.34375
28,167
How many distinct four-digit positive integers have a digit product equal to 18?
48
0
28,168
In the xy-plane, consider a right triangle $ABC$ with the right angle at $C$. The hypotenuse $AB$ is of length $50$. The medians through vertices $A$ and $B$ are described by the lines $y = x + 5$ and $y = 2x + 2$, respectively. Determine the area of triangle $ABC$.
500
2.34375
28,169
Initially, the numbers 1 and 2 are written at opposite positions on a circle. Each operation consists of writing the sum of two adjacent numbers between them. For example, the first operation writes two 3's, and the second operation writes two 4's and two 5's. After each operation, the sum of all the numbers becomes three times the previous total. After sufficient operations, find the sum of the counts of the numbers 2015 and 2016 that are written.
2016
0
28,170
The Wolf and the three little pigs wrote a detective story "The Three Little Pigs-2", and then, together with Little Red Riding Hood and her grandmother, a cookbook "Little Red Riding Hood-2". The publisher gave the fee for both books to the pig Naf-Naf. He took his share and handed the remaining 2100 gold coins to the Wolf. The fee for each book is divided equally among its authors. How much money should the Wolf take for himself?
700
10.15625
28,171
Given non-zero vectors $\overrightarrow{a}$ and $\overrightarrow{b}$ satisfy $|\overrightarrow{a}|=2|\overrightarrow{b}|$, and $(\overrightarrow{a}-\overrightarrow{b})\bot \overrightarrow{b}$, calculate the angle between $\overrightarrow{a}$ and $\overrightarrow{b}$.
\frac{\pi}{3}
98.4375
28,172
The houses on the south side of Crazy Street are numbered in increasing order starting at 1 and using consecutive odd numbers, except that odd numbers that contain the digit 3 are missed out. What is the number of the 20th house on the south side of Crazy Street?
59
53.90625
28,173
How many two-digit numbers have digits whose sum is a prime number?
31
0
28,174
Seven cards numbered $1$ through $7$ are to be lined up in a row. Find the number of arrangements of these seven cards where one of the cards can be removed leaving the remaining six cards in either ascending or descending order.
26
0.78125
28,175
Given that $(2x)_((-1)^{5}=a_0+a_1x+a_2x^2+...+a_5x^5$, find: (1) $a_0+a_1+...+a_5$; (2) $|a_0|+|a_1|+...+|a_5|$; (3) $a_1+a_3+a_5$; (4) $(a_0+a_2+a_4)^2-(a_1+a_3+a_5)^2$.
-243
12.5
28,176
Let $a,$ $b,$ $c$ be real numbers such that $9a^2 + 4b^2 + 25c^2 = 1.$ Find the maximum value of \[8a + 3b + 5c.\]
\frac{\sqrt{373}}{6}
77.34375
28,177
Find the smallest natural number \( n \) such that both \( n^2 \) and \( (n+1)^2 \) contain the digit 7.
27
8.59375
28,178
Given the sequence $\{a\_n\}(n=1,2,3,...,2016)$, circle $C\_1$: $x^{2}+y^{2}-4x-4y=0$, circle $C\_2$: $x^{2}+y^{2}-2a_{n}x-2a_{2017-n}y=0$. If circle $C\_2$ bisects the circumference of circle $C\_1$, then the sum of all terms in the sequence $\{a\_n\}$ is $\_\_\_\_\_\_$.
4032
71.09375
28,179
Let $\triangle ABC$ be a right triangle with $\angle ABC = 90^\circ$, and let $AB = 10\sqrt{21}$ be the hypotenuse. Point $E$ lies on $AB$ such that $AE = 10\sqrt{7}$ and $EB = 20\sqrt{7}$. Let $F$ be the foot of the altitude from $C$ to $AB$. Find the distance $EF$. Express $EF$ in the form $m\sqrt{n}$ where $m$ and $n$ are positive integers and $n$ is not divisible by the square of any prime. Find $m + n$.
31
5.46875
28,180
How many non-empty subsets $S$ of $\{1, 2, 3, \ldots, 10\}$ satisfy the following two conditions? 1. No two consecutive integers belong to $S$. 2. If $S$ contains $k$ elements, then $S$ contains no number less than $k$.
59
0
28,181
Two adjacent faces of a tetrahedron, which are equilateral triangles with side length 3, form a dihedral angle of 30 degrees. The tetrahedron rotates around the common edge of these faces. Find the maximum area of the projection of the rotating tetrahedron onto the plane containing this edge.
\frac{9 \sqrt{3}}{4}
26.5625
28,182
For a nonnegative integer $n$, let $r_7(3n)$ represent the remainder when $3n$ is divided by $7$. Determine the $22^{\text{nd}}$ entry in an ordered list of all nonnegative integers $n$ that satisfy $$r_7(3n)\le 4~.$$
29
5.46875
28,183
Find the greatest common divisor of $8!$ and $(6!)^2.$
5760
76.5625
28,184
A district in a city is laid out in an $11 \times 11$ grid. Every day, a sprinkler truck departs from the bottom-left corner $A(0,0)$ and travels along the streets to reach the top-right corner $B(10,10)$. At each intersection, the driver randomly chooses a direction, as long as it does not deviate from the shortest path. One day, the street from $(9,9)$ to $(10,9)$ is blocked due to an accident, but the driver is not aware of this at the time of departure. What is the probability that the sprinkler truck can still reach $B$ without any issues?
1 - \frac{\binom{18}{9}}{\binom{20}{10}}
0
28,185
Evaluate $|\omega^2 + 4\omega + 34|$ if $\omega = 5 + 3i$.
\sqrt{6664}
0
28,186
From the numbers 2, 3, 4, 5, 6, 7, 8, 9, two different numbers are selected to be the base and the exponent of a logarithm, respectively. How many different logarithmic values can be formed?
52
8.59375
28,187
Let $ABC$ be a triangle with side lengths $AB=6, AC=7,$ and $BC=8.$ Let $H$ be the orthocenter of $\triangle ABC$ and $H'$ be the reflection of $H$ across the midpoint $M$ of $BC.$ $\tfrac{[ABH']}{[ACH']}$ can be expressed as $\frac{p}{q}$ . Find $p+q$ . *2022 CCA Math Bonanza Individual Round #14*
251
0
28,188
What is the smallest positive integer with exactly 12 positive integer divisors?
72
0
28,189
Let \( g_{1}(x) = \sqrt{4 - x} \), and for integers \( n \geq 2 \), define \[ g_{n}(x) = g_{n-1}\left(\sqrt{(n+1)^2 - x}\right). \] Find the largest \( n \) (denote this as \( M \)) for which the domain of \( g_n \) is nonempty. For this value of \( M \), if the domain of \( g_M \) consists of a single point \( \{d\} \), compute \( d \).
-589
0
28,190
A rectangular table $ 9$ rows $ \times$ $ 2008$ columns is fulfilled with numbers $ 1$ , $ 2$ , ..., $ 2008$ in a such way that each number appears exactly $ 9$ times in table and difference between any two numbers from same column is not greater than $ 3$ . What is maximum value of minimum sum in column (with minimal sum)?
24
1.5625
28,191
Given that $15^{-1} \equiv 31 \pmod{53}$, find $38^{-1} \pmod{53}$, as a residue modulo 53.
22
67.96875
28,192
Given that there are 20 cards numbered from 1 to 20 on a table, and Xiao Ming picks out 2 cards such that the number on one card is 2 more than twice the number on the other card, find the maximum number of cards Xiao Ming can pick.
12
14.0625
28,193
Given the piecewise function $f(x)= \begin{cases} x+2 & (x\leq-1) \\ x^{2} & (-1<x<2) \\ 2x & (x\geq2)\end{cases}$, if $f(x)=3$, determine the value of $x$.
\sqrt{3}
54.6875
28,194
The graph of the equation $10x + 270y = 2700$ is drawn on graph paper where each square represents one unit in each direction. A second line defined by $x + y = 10$ also passes through the graph. How many of the $1$ by $1$ graph paper squares have interiors lying entirely below both graphs and entirely in the first quadrant?
50
3.125
28,195
A rectangular pasture is to be fenced off on three sides using part of a 100 meter rock wall as the fourth side. Fence posts are to be placed every 15 meters along the fence including at the points where the fence meets the rock wall. Given the dimensions of the pasture are 36 m by 75 m, find the minimum number of posts required.
14
11.71875
28,196
In a Cartesian coordinate plane, call a rectangle $standard$ if all of its sides are parallel to the $x$ - and $y$ - axes, and call a set of points $nice$ if no two of them have the same $x$ - or $y$ - coordinate. First, Bert chooses a nice set $B$ of $2016$ points in the coordinate plane. To mess with Bert, Ernie then chooses a set $E$ of $n$ points in the coordinate plane such that $B\cup E$ is a nice set with $2016+n$ points. Bert returns and then miraculously notices that there does not exist a standard rectangle that contains at least two points in $B$ and no points in $E$ in its interior. For a given nice set $B$ that Bert chooses, define $f(B)$ as the smallest positive integer $n$ such that Ernie can find a nice set $E$ of size $n$ with the aforementioned properties. Help Bert determine the minimum and maximum possible values of $f(B)$ . *Yannick Yao*
2015
39.0625
28,197
Two lines with slopes $\dfrac{1}{3}$ and $3$ intersect at $(3,3)$. Find the area of the triangle enclosed by these two lines and the line $x+y=12$.
8.625
0
28,198
A function is given by $$ f(x)=\ln (a x+b)+x^{2} \quad (a \neq 0). $$ (1) If the tangent line to the curve $y=f(x)$ at the point $(1, f(1))$ is $y=x$, find the values of $a$ and $b$. (2) If $f(x) \leqslant x^{2}+x$ always holds, find the maximum value of $ab$.
\frac{e}{2}
20.3125
28,199
The inclination angle $\alpha$ of the line $l: \sqrt{3}x+3y+1=0$ is $\tan^{-1}\left( -\frac{\sqrt{3}}{3} \right)$. Calculate the value of the angle $\alpha$.
\frac{5\pi}{6}
71.09375