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mathematics
|
The price of a T.V. set worth Rs. 20000 is to be paid in 20 installments of Rs. 1000 each. If the rate of interest be 6% per annum, and the first installment be paid at the time of purchase, then the value of the last installment covering the interest as well will be?
|
[
"22678",
"26699",
"26788",
"19000",
"26711"
] |
Money paid in cash = Rs. 1000
Balance payment = (20000 - 1000) = Rs. 19000
Answer: D
The answer is: D
|
D
|
mathematics
|
In a renowned city, the average birth rate is 7 people every two seconds and the death rate is 1 people every two seconds. Estimate the size of the population net increase that occurs in one day.
|
[
"32,300",
"172,800",
"468,830",
"338,200",
"259,200"
] |
Every 2 seconds, 6 persons are added (7-1). Every second 3 persons are added.
In a day 24hrs = 24 * 60 Minutes = 24 * 60 * 60 = 86400 seconds.
86400 * 3 = 259200
Option E
The answer is: E
|
E
|
mathematics
|
A ladies hostel had provision of food for 300 women for 45 days. After 10 days, 275 women left the hostel. The number of days for which the remaining food will last is:
|
[
"420",
"430",
"450",
"480",
"425"
] |
Explanation :
After 10 days : 300 women had food for 35 days.
Suppose 25 women had food for x days.
Now, Less women, More days (Indirect Proportion)
25 : 300 :: 35 : x
=> 25 x x = 300 x 35
=> x = 300 x 35 / 25
=> x = 420
Answer : A
The answer is: A
|
A
|
mathematics
|
The cost price of 13 articles is equal to the selling price of 11 articles. Find the profit percent?
|
[
"18 2/19%",
"18 2/11%",
"18 2/91%",
"18 2/81%",
"18 2/121%"
] |
13 CP = 11 SP
11 --- 2 CP
100 --- ? =>18 2/11%
Answer: B
The answer is: B
|
B
|
mathematics
|
A “Sophie Germain” prime is any positive prime number p for which 2p + 1 is also prime. The product of all the possible units digits of Sophie Germain primes greater than 6 is
|
[
"3",
"7",
"21",
"189",
"198"
] |
In that case, the Sophie prime numbers greater than 6 are 7,11,23,47,59, .. which yields units digit as 1,3,7 and 9
Product would be 1 x 3 x 7x9 =189 Answer should be D
The answer is: D
|
D
|
mathematics
|
The average weight of 8 person's increases by 3.5 kg when a new person comes in place of one of them weighing 65 kg. What is the weight of the new person?
|
[
"93 Kg",
"50 Kg",
"85 Kg",
"80 Kg",
"60 KG"
] |
Explanation:
Total increase in weight = 8 × 3.5 = 28
If x is the weight of the new person, total increase in weight = x−65
=> 28 = x - 65
=> x = 28 + 65 = 93
Answer: Option A
The answer is: A
|
A
|
mathematics
|
There are m cities. What is the number of airlines that connected 2 different cities (airline from city A to city B is different with airline from city B to city A)?
|
[
"n(n-1)",
"m(m-1)",
"n(n-1)/2",
"n(n+1)/2",
"n2"
] |
First of all, the possible number of airlines is m. Then, the possible number of airlines departing from one city to another becomes (m-1). Hence, the answer is m(m-1), which makes A an answer choice.
B
The answer is: B
|
B
|
mathematics
|
If x^2=3x+1, then x^3 = ?
|
[
"8x+2",
"10x+3",
"6x+1",
"2x+3",
"6x+4"
] |
x^2 = 3x+1
x^3 = x*x^2 = x*(3x+1) = 3x^2 + x = 3(3x+1)+x = 10x+3
The answer is B.
The answer is: B
|
B
|
mathematics
|
Set A = {1, 2, 3, 4, 5, 6, y}
Which of the following possible values for y would cause Set A to have the smallest standard deviation?
|
[
"1",
"2.5",
"3",
"3.5",
"7"
] |
SD is minimum or least when the number is closest to the mean of the existing numbers
Calculating mean of the rest of the numbers gives mean = (approx)3.6
So the new number should be near to the mean and only number closest to the mean is 3.5
Answer: Option D
The answer is: D
|
D
|
mathematics
|
Pam and Stanley packed several boxes with reams of paper. While both packed, Pam packed 40% of the boxes. After Pam stopped, Stanley packed the same number of boxes that he had packed while working with Pam. What is the ratio of the number of boxes Pam packed to the number of boxes Stanley packed?
|
[
"2 to 6",
"1 to 3",
"3 to 5",
"3 to 4",
"3 to 2"
] |
Correct Answer: A
Solution: A. We know that when Pam and Stanley were both working, the ratio was 2 boxes by Pam to 3 boxes by Stanley. We also know that Stanley continued working after Pam stopped. He packed as many boxes alone as he had packed whlie working with Pam, effectively doubling his number of boxes. Thus, the ratio of Pam's boxes to Stanley's boxes is 2 to 6. Answer A is correct.
The answer is: A
|
A
|
mathematics
|
A person covered one-fourth of the total distance at 26 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?
|
[
"21 (1/36)kmph",
"21 (1/3)kmph",
"21 (8/3)kmph",
"27 (1/3)kmph",
"25 (1/3)kmph"
] |
Let the total distance be x km
total time taken = (x/4)/16 + (3x/4)/24
= x/64 + x/32 = 3x/64
Average speed = x/(3x/64)
= 64/3kmph
= 21 (1/3)kmph.
Answer: B
The answer is: B
|
B
|
mathematics
|
Steel company has four empty trucks that will head out in the morning, all four to the same destination. The clerk has four different boxes to ship to that same destination. All four boxes could go on any one of the trucks, or the boxes could be split up into any groupings and given to the trucks in any combinations (ie. two to one truck, one to another, and one to another). In how many different ways could the boxes be put on the four trucks?
|
[
"16",
"64",
"256",
"576",
"4096"
] |
MAGOOSHOFFICIAL SOLUTION:
Steel company has four empty trucks that will head out in the morning, all four to the same destination.Where we put one box has absolutely no bearing on where we put any of the other boxes. The placement of the four boxes is completely independent of one another. For each box, we have four choices.
N = 4*4*4*4 = 16*16 = 256
Answer = (C)
The answer is: C
|
C
|
mathematics
|
Roger can read a book in k minutes. What part of the book can he read in 7 minutes? (k>8)
|
[
"8+k",
"k/8",
"7/k",
"(k+ 8)/k",
"(k-8) / k"
] |
Let's sayk = 24
That is, it takes 24 minutes to read the entire book.
So, in 8 minutes, Roger can read1/3of the book
So, we're looking for the answer choice that yields an OUTPUT of1/3whenk = 24
A) 8+24=32ELIMINATE
B) 8/24=1/3KEEP
C)24/8 =3ELIMINATE
D) (24+ 8)/24=32/24 = 4/3ELIMINATE
E) (24-8) /24=16/24 = 2/3ELIMINATE
Answer: C
The answer is: C
|
C
|
mathematics
|
In the formula V = 1/(2r)^4, if r is halved, then V is multiplied by?
|
[
"16",
"8",
"1",
"1/8",
"1/64"
] |
Say r=2 => V1 = 1/256
when r=1; V2 = 1/16
V2 = 16*V1.
Answer : A
The answer is: A
|
A
|
mathematics
|
What is the units digit of 23^2 * 17^2 * 39^2?
|
[
"1",
"3",
"5",
"7",
"9"
] |
The units digit of 23^2 is the units digit of 3*3 = 9 which is 9.
The units digit of 17^2 is the units digit of 7*7 = 49 which is 9.
The units digit of 39^2 is the units digit of 9*9 = 81 which is 1.
The units digit of 9*9*1 = 81 is 1.
The answer is A.
The answer is: A
|
A
|
mathematics
|
In a contest, a bowl contains 5 keys, one of which will open a treasure chest and Four of which will not. If a contestant selects the key that opens the treasure chest, she wins the contents of that chest. If priya is allowed to draw two keys, simultaneously and at random, from the bowl as the first contestant, what is the probability that she wins the prize?
|
[
"2/7",
"2/5",
"2/9",
"2/11",
"2/13"
] |
The total possibilities existing while withdrawing two keys are: 5C2 = 10
For priya to win, 4 combinations exist assuming Key 1 to unlock the treasure E.g(1,2), (1,3)....(1,4)
P = 4/10= 2/5
Option B
The answer is: B
|
B
|
mathematics
|
Some part of a 50% solution of acid was replaced with an equal amount of 30% solution of acid. If, as a result, 40% solution of acid was obtained, what part of the original solution was replaced?
|
[
"1/5",
"1/4",
"1/2",
"3/4",
"4/5"
] |
Original Acid : Total ratio = 50:100 . let us say you replaced x part of this. So you are left with (1-x) of the original. So volume of acid left is (1-x)50.
in the new solution.. you added x of 30% solution. i.e 30x acid
(1-x)50 + 30x is the volume of acid. The total volume is still 100. And this concentration is 40%
[(1-x)50 + 30x] / 100 = 40/100
solve to get x=1/2
ANSWER:C
The answer is: C
|
C
|
mathematics
|
The purchase price of an article is $48. In order to include 25% of cost for overhead and to provide $12 of net profit, the markup should be
|
[
"50%",
"25%",
"35%",
"40%",
"45%"
] |
Cost price of article = 48$
% of overhead cost = 25
Net profit = 12 $
We need to calculate % markup
Net profit as % of cost price = (12/48)*100 = 25%
Total markup should be = 25 + 25 = 50%
Answer A
The answer is: A
|
A
|
mathematics
|
Excluding stoppages, the speed of a bus is 54 km/hr and including stoppages, it is 45 km/hr. For how many minutes does the bus stop per hour?
|
[
"11 min",
"10 min",
"37 min",
"17 min",
"16 min"
] |
Due to stoppages, it covers 9 km less.
Time taken to cover 9 km
= 9/54 * 60 = 10 min.
Answer: B
The answer is: B
|
B
|
mathematics
|
three men invested sum. and their ratio is 5:7:6. profit is 900.then b's share
|
[
"2000",
"2100",
"2200",
"350",
"2400"
] |
b's share =7/18*900=350
ANSWER:D
The answer is: D
|
D
|
mathematics
|
Shekar scored 76, 65, 82, 62 and 85 marks in Mathematics, Science, Social studies, English and Biology respectively. What are his average marks?
|
[
"74",
"69",
"75",
"85",
"90"
] |
Explanation :
Average= (76+65+82+62+85)/5 = 370/5 =74
Hence average=74
Answer : A
The answer is: A
|
A
|
mathematics
|
When the integer k is divided by 7, the remainder is 6. Which of the following expressions below when divided by 7, will have a remainder of 5?
I. 4k + 2
II. 6k + 4
III. 8k + 3
|
[
"I only",
"II only",
"III only",
"I and II only",
"I, II and III"
] |
k = 7j + 6
4k + 2 = 28j + 24 + 2 = 28j + 21 + 5
6k + 4 = 42j + 36 + 4 = 42j + 35 + 5
8k + 3 = 56j + 48 + 3 = 56j + 49 + 2
The answer is D.
The answer is: D
|
D
|
mathematics
|
A reduction of 25% in the price of oil enables a house wife to obtain 5kgs more for Rs.800, what is the reduced price for kg?
|
[
"55",
"66",
"40",
"88",
"12"
] |
800*(25/100) = 200 ---- 5
? ---- 1 => Rs.40
Answer:C
The answer is: C
|
C
|
mathematics
|
How many digits are in (8×10^14)(10×10^10)?
|
[
"24",
"25",
"26",
"27",
"28"
] |
he question simplifies to (8×10^14)(10^11)
=> 8*10^25
=> Will contain 25 zeros +1 digit 8
=>26
Ans C
The answer is: C
|
C
|
mathematics
|
180,131,95,70,?
|
[
"42",
"43",
"54",
"40",
"39"
] |
180 - 131 = 49 = 7^2
131 - 95 = 36 = 6^2
95 - 70 = 25 = 5^2
so we can write
70 - x = 16 = 4^2 , where x is the next number
x = 70 - 16 = 54
so the next number will be 54
ANSWER:C
The answer is: C
|
C
|
mathematics
|
50% of the apartments in a certain building have windows and hardwood floors. 25% of the apartments without windows have hardwood floors. If 40% of the apartments do not have hardwood floors, what V percent of the apartments with windows have hardwood floors?
|
[
"10",
"16 2/3",
"40",
"50",
"83 1/3"
] |
yup you need to construct a matrix
X********| Windows'|No Windows'''| total
hardFl****'|50*****''|10*********'|60
Not hardFl*|10******|30*********'|40
Total*****|60******'|40*********'|100
so V percent of the apartments with windows have hardwood floors = 50/60 *100
= 83 1/3
so E is the answer.[/u]
The answer is: E
|
E
|
mathematics
|
Abby and Bobby type at constant rates of 70 words per minute and 60 words per minute, respectively. Bobby begins typing before Abby and has typed 600 words when Abby begins typing at 1:30 pm. If they continue typing at their respective rates, at what time will Abby have typed exactly 200 more words than Bobby?
|
[
"1:40 PM",
"2:50 PM",
"2:00 PM",
"2:10 PM",
"2:20 PM"
] |
Say time needed for Abby to type 200 more words than Bobby is t. In that time she would type 70t words and Bobby would type 60t words.
Now, total words typed by Bobby would be 600+60t and we want that number to be 200 less than 70t: 600+60t=70t-200 --> t=80.
1:30 PM + 80 minutes = 2:50 PM.
Answer: B.
The answer is: B
|
B
|
mathematics
|
An equilateral triangle T2 is formed by joining the mid points of the sides of another equilateral triangle T1. A third equilateral triangle T3 is formed by joining the mid-points of T2 and this process is continued indefinitely. If each side of T1 is 30 cm, find the sum of the perimeters of all the triangles.
|
[
"180 cm",
"220 cm",
"240 cm",
"270 cm",
"300 cm"
] |
We have 30 for first triangle, when we join mid-points of first triangle we get the second equilateral triangle then the length of second one is 15 and continues.
So we have 30,15,7.5,...
We have ratio = 1/2, and it is GP type.
Sum of infinite triangle is a/1-r = 30/1-(1/2) = 60
Equilateral triangle perimeter is 3a = 3*60 = 180.
So option A.
The answer is: A
|
A
|
mathematics
|
A number is selected at random from the first 40 natural numbers. What is the probability that the number is a multiple of either 2 or 21?
|
[
"21/40",
"2/5",
"7/15",
"4/15",
"11/30"
] |
Number of Multiples of 2 from 1 through 40 = 40/2 = 20
Number of Multiples of 21 from 1 through 40 = 40/21 = 1
Number of Multiples of 2 and 21 both from 1 through 40 = Number of Multiples of 21*2(=42) = 0
Total favourable cases = 20 + 1 - 0 = 21
Probability = 21 / 40
Answer: option A
The answer is: A
|
A
|
mathematics
|
A palindrome is a number that reads the same front-to-back as it does back-to-front (e.g. 202, 575, 1991, etc.) p is the smallest integer greater than 100 that is both a prime and a palindrome. What is the sum of the digits of p?
|
[
"3",
"4",
"5",
"6",
"7"
] |
Given that p is smallest integer greater than 200 - assume there is a 3-digit that satisfies the above conditions. Let the number be xyx ; question asks us the values of 2x+y
We can straight away cross out options A) and D) - sum of digits 3 or 6 implies it is divisible by 3 ---> we know that p is a prime number
Coming to option B) 2x + y = 4 --> only x = 2 and y = 0 satisfy this equation ( x> 2 will never give sum of digits = 4) ; but 202 is divisible by 2 ; we know that p is a prime number
Similarly option C) 2x+y = 5 --> only x = 2 and y = 1 satisfy this equation ( x> 2 will never give sum of digits = 5) ; but 212 is divisible by 2 ; we know that p is a prime number
Therefore answer option should be E ---> can be verified by taking 2x+y = 7 ---> x = 3 and y = 1 ; gives 313
C
The answer is: C
|
C
|
mathematics
|
Think of a number, divide it by 6 and add 5 to it. The result is 17. What is the number thought of?
|
[
"24",
"72",
"297",
"267",
"29"
] |
Explanation :
17-5 = 12
12 x 6 = 72
Answer : B
The answer is: B
|
B
|
mathematics
|
You have a bag of 9 letters: 3 Xs, 3 Ys and 3 Zs. You are given a box divided into 3 rows and 3 columns for a total of 9 areas. How many Q different ways can you place one letter into each area such that there are no rows or columns with 2 or more of the same letter?
|
[
"5",
"6",
"9",
"12",
"18"
] |
Consider one particular arrangement of the first row: XYZ, then we can construct only two boxes with so that no rows or columns have 2 or more of the same letter:
XYZ
YZX
ZXY
And:
XYZ
ZXY
YZX
Now, the first row itself can be arranged in 3!=6 ways (since there are three distinct letter), hence the total number of boxes possible Q is 2*6=12.
Answer: D.
The answer is: D
|
D
|
mathematics
|
Two unbiased coins are tossed.What is the probability of getting at most one head?
|
[
"2/3",
"1",
"3/4",
"2",
"1/2"
] |
s={hh,tt,ht,th}
e=event of getting at most one head.
e={tt,ht,th}.
p(e)=n(e)/n(s)=3/4
Answer is option C
The answer is: C
|
C
|
mathematics
|
The total marks obtained by a student in Mathematics and Physics is 60 and his score in Chemistry is 20 marks more than that in Physics. Find the average marks scored in Mathamatics and Chemistry together.
|
[
"40",
"30",
"25",
"Data inadequate",
"None of these."
] |
Let the marks obtained by the student in Mathematics, Physics and Chemistry be M, P and C respectively.
Given , M + C = 60 and C - P = 20 M + C / 2 = [(M + P) + (C - P)] / 2 = (60 + 20) / 2 = 40.
ANSWER:A
The answer is: A
|
A
|
mathematics
|
A tradesman by means of his false balance defrauds to the extent of 28%? in buying goods as well as by selling the goods. What percent does he gain on his outlay?
|
[
"44%",
"48%",
"94%",
"45%",
"64%"
] |
g% = 28 + 28 + (28*28)/100
= 64%
Answer: E
The answer is: E
|
E
|
mathematics
|
Two pens and three pencils cost 86. Four pens and a pencil cost 112. What is the difference between the cost of a pen and that of a pencil?
|
[
"25",
"13",
"19",
"Cannot be determined",
"None of these"
] |
Let the cost of a pen and a pencil be ‘x’ and ‘y’ respectively. We have to find (x – y).
From the question,
2x + 3y = 86 ..... (i)
4x + y = 112 ......(ii)
Subtracting (i) from (ii), we get
2x – 2y = 26 or, x – y = 13
Answer B
The answer is: B
|
B
|
mathematics
|
If p and q are positive integers, how many integers are larger than pq and smaller than p(q + 3)?
|
[
"3",
"P + 2",
"p – 2",
"3p – 1",
"2p + 1"
] |
The number of integers between x and y, where x>y is (x-y)-1. For example, the number of integers between 1 and 5 is (5-1)-1=3: 2, 3, and 4.
Thus, the number of integers between pq and p(q+3)=pq+3p is (pq+3p-pq)-1=3p-1.
Answer: D.
The answer is: D
|
D
|
mathematics
|
If each side of a square is increased by 25%, find the percentage change in its area?
|
[
"54%",
"56%",
"56.25%",
"58.25%",
"59%"
] |
let each side of the square be a , then area = a x a
New side = 125a / 100 = 5a / 4
New area =(5a x 5a) / (4 x 4) = (25a²/16)
increased area== (25a²/16) - a²
Increase %= [(9a²/16 ) x (1/a² ) x 100]% = 56.25%
answer :C
The answer is: C
|
C
|
mathematics
|
What least number must be subtracted from 12702 to get number exactly 99 ?
|
[
"49",
"30",
"29",
"31",
"32"
] |
Explanation:
Divide the given number by 99 and find the remainder. If you subtract the remainder from the given number then it is exactly divisible by 99.
99) 12702 (128
99
280
198
822
792
30
Required number is 30.
ANSWER IS B
The answer is: B
|
B
|
mathematics
|
A bowl contains pecans, cashews, and almonds in a ratio of 3 : 4 : 6, respectively. If some of the nuts of one of the three types are removed, which of the following could be the ratio of pecans to cashews to almonds remaining in the bowl? i. 1 : 2 : 3 ii. 2 : 3 : 4 iii. 4 : 7 : 10
|
[
"II only",
"I,II only",
"III only",
"I,III only",
"I only"
] |
i. The ratio 2 : 3 is the same as the given ratio 4 : 6. If one pecan were removed, the new ratio would be 2 : 4 : 6, or 1 : 2 : 3.
ii. None of the nuts currently have a ratio of 3 : 4. The cashews and almonds do have a ratio of 2 : 3, but there are not enough pecans in the bowl to complete the ratio.
iii. The ratio 4 : 10 is the same as the given ratio 6 : 15. To see this, multiply the ratio by 3/2 . The new ratio is 6 : 10.5 : 15. Unfortunately, this means that there are fewer cashews that this ratio would require. Removing cashews won’t create the desired ratio.
Answer : E
The answer is: E
|
E
|
mathematics
|
Two trains of equal are running on parallel lines in the same direction at 48km/hr and 36 km/hr. The faster train passes the slower train in 36 sec. The length of each train is?
|
[
"50",
"88",
"60",
"55",
"22"
] |
Let the length of each train be x m.
Then, distance covered = 2x m.
Relative speed = 48 - 36 = 12 km/hr.
= 12 * 5/18 = 10/3 m/sec.
2x/36 = 10/3 => x = 60.
Answer:C
The answer is: C
|
C
|
mathematics
|
Tanya prepared 4 different letters to be sent to 4 different addresses. For each letter she prepared an envelope with its correct address. If the 4 letters are to be put in 4 envelopes at random, what is the probability that only 1 letter will be put into the envelope with its correct address?
|
[
"1/24",
"1/8",
"1/4",
"1/3",
"3/8"
] |
Possible sequences are CIII, ICII, and so on...C=correct, I=incorrect
Total possible sequences are 4P1=4 ways.
Lets take the probability of having one particular sequence CIII.
P = 1/4*2/3*1/2*1 = 1/12.
So the probability of having any of the sequence is 4*1/12 =1/3
ANS:D
The answer is: D
|
D
|
mathematics
|
Thirty percent of the women in a college class are science majors, and the non-science majors make up 80% of the class. What percentage of the women are science majors if 40% of the class are men?
|
[
"2%",
"5%",
"28%",
"30%",
"45%"
] |
3/k + 2/m = 6/t
Assuming total # is 100 :
[Science - Women] will have - 0.3 * 60 = 18
[Non-Science-Women] will have - 42
[Science-Men] will have = 20-18 = 2
S0 18/60 * 100 = 30%
Answer - D
The answer is: D
|
D
|
mathematics
|
In a kilometer race, A beats B by 40 meters or 10 seconds. What time does A take to complete the race?
|
[
"167 sec",
"190 sec",
"176 sec",
"240 sec",
"123 sec"
] |
Time taken by B run 1000 meters
= (1000 * 10)/40 = 250 sec.
Time taken by A = 250 - 10
= 240 sec.
Answer:D
The answer is: D
|
D
|
mathematics
|
A coin is tossed 4 times. What is the probability a that the number of Heads is equal to the number of Tails?
|
[
"1/8",
"1/4",
"3/8",
"1/2",
"9/16"
] |
We have to find the probability that we get 2 heads and 2 tails in 4 tosses of the coin.
Using the binary formula and defining a head as a success,
P(2 heads in 4 tosses) = 4C2* (1/2)^2 * (1/2)^2
= 6/16
a= 3/8
The answer is therefore (C)
The answer is: C
|
C
|
mathematics
|
In the xy-plane, the points (c, d), (c, -d), and (-c, -d) are three vertices of a certain square. If c < 0 and d > 0, which of the following points R is in the same quadrant as the fourth vertex of the square?
|
[
"(-5, -3)",
"(-5, 3)",
"(5, -3)",
"(3, -5)",
"(3, 5)"
] |
The question:In the xy-plane, the points (c, d), (c, -d), and (-c, -d) are three vertices of a certain square.If c < 0 and d > 0,which of the following points R is in the same quadrant as the fourth vertex of the square?
I marked the tricky part in red. It seems c is anegativenumber and d is a positive number. This means
Vertex #1 = (c, d) is in QII (that is, negative x and positive y)
Vertex #2 = (c, -d) is in QIII (that is, both xy negative)
Vertex #3 = (-c, -d) is in QIV (that is y is negative, but x is positive)
That means the last vertex should be in the first quadrant --- the only first quadrant point is (5, 3), answer =E.
The answer is: E
|
E
|
mathematics
|
Find the greatest number that will divide 150, 230 and 175 leaving 50, 5 and 25 as remainders respectively
|
[
"19",
"17",
"32",
"9",
"8"
] |
Explanation:
Answer will be HCF of (150-50, 230-5, 175-25)
HCF of (100, 225, 150) = 32
Option C
The answer is: C
|
C
|
mathematics
|
The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is:
|
[
"35 years",
"40 years",
"50 years",
"45 years",
"None of these"
] |
Sum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90 years.
Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years.
Husband's present age = (90 - 50) years = 40 years.
Answer: Option B
The answer is: B
|
B
|
mathematics
|
The integer x is divisible by both 9 and 36. Which of the following must be an integer?
|
[
"x/16",
"x/36",
"x/25",
"x/46",
"x/24"
] |
Prime factorization of 9 = 3^2
Prime factorization of 36= 3^2*2^2
LCM of 9 and 36 = 3^2 * 2^2 = 36
Therefore x/36 must be an integer
Answer B
The answer is: B
|
B
|
mathematics
|
If t>0.9, which of the following options can be the value of t?
|
[
"0.9^2",
"√(0.9)",
"0.09",
"0.9",
"0.9^3"
] |
Lets take a few examples
When .2 is squared it gives .04
when .5 is squared it gives .25
When .9 is squared it gives .81
So raising a fraction to its power of 2 or 3 only reduces the value of the fraction
This is because
.2 = 2/10
.2^2= 4/100
.2^3=8/1000
Since the denominator gets an extra 0 each time u increase the power , it is going to drag the value down
But if you just think about the opposite case :
Then we can see , if squaring a fraction diminish its value, then taking the square root of it will again increase its value
that is √(0.04) will give you back 0.2
so √(0.04) > 0.04
so obviously diminishing the power will appreciate the value
So t √(0.9) > 0.9
Hence Correct Answer is (B)
The answer is: B
|
B
|
mathematics
|
A trader mixes 80 kg of tea at 15 per kg with 20 kg of tea at cost price of 20 per kg. In order to earn a profit of 35%, what should be the sale price of the mixed tea?
|
[
"23.75",
"21.6",
"20",
"19.2",
"None of these"
] |
C.P. of mixture = 80×15+20×20 /80+20=16
∴ S.P. = (100+35)/100×16=21.6
Answer B
The answer is: B
|
B
|
mathematics
|
Rs.20 is the true discount on Rs. 260 due after a certain time. What will be the true discount on the same sum due after half of the former time, the rate of interest being the same?
|
[
"10.4",
"11",
"14.8",
"15.4",
"none"
] |
Sol.
S.I. on Rs. (260 - 20) for a given time = Rs. 20.
S.I. on Rs. 240 for half the time = Rs. 10.
T.D. on Rs. 250 = Rs. 10.
∴ T.D. on Rs. 260 = Rs. [10/250 * 260] = Rs. 10.40
Answer A
The answer is: A
|
A
|
mathematics
|
A retailer sells 10 shirts. The first 3 he sells for $20,$22 and $25. If the retailer wishes to sell the 10 shirts for an overall average price of over $20, what must be the minimum average price of the remaining 7 shirts?
|
[
"$14.00",
"$16.00",
"$17.00",
"$19.00",
"$23.00"
] |
First 3 shirts are sold for $20,$22 and $25=$67.
To get average price of $20,total sale should be 10*$20=$200
So remaining 7 shirts to be sold for $200-$67=$133
Answer should be 133/7=$19.00 that is D
The answer is: D
|
D
|
mathematics
|
A number is increased by 70 % and then decreased by 70 %. Find the net increase or decrease per cent.
|
[
"49%",
"18%",
"17%",
"13%",
"16%"
] |
Let the number be 100.
Increase in the number = 70 % = 70 % of 100
= (70/100 × 100)
= 70
Therefore, increased number = 100 + 70 = 170
This number is decreased by 70 %
Therefore, decrease in number = 70 % of 170
= (70/100 × 170)
= 11900/100
= 119
Therefore, new number = 170 - 119 = 51
Thus, net decreases = 100 - 51 = 49
Hence, net percentage decrease = (49/100 × 100) %
= (4900/100) %
= 49 %
Answer:A
The answer is: A
|
A
|
mathematics
|
The average weight of 8 people increases by 2.5 kg when a new person comes in place of one of them weighing 35 kg. What is the weight of the new person?
|
[
"75 kg",
"85 kg",
"95 kg",
"65 kg",
"55 kg"
] |
The total weight increase = (8 x 2.5) kg = 20 kg
weight of new person = (35 + 20) kg = 55 kg
The answer is E.
The answer is: E
|
E
|
mathematics
|
A box contains 3 blue marbles, 4 red, 6 green marbles and 2 yellow marbles. If three marbles are picked at random, what is the probability that they are all blue?
|
[
"1/455",
"1/429",
"1/408",
"1/421",
"1/420"
] |
Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles.
Probability that all the three marbles picked at random are blue
= ³C₃/¹⁵C₃ = (1 * 3 * 2 * 1)/(15 * 14 * 13)
= 1/455
Answer: A
The answer is: A
|
A
|
mathematics
|
The L.C.M of two numbers is 48. The numbers are in the ratio 2:3. The sum of numbers is?
|
[
"22",
"67",
"40",
"88",
"11"
] |
Let the numbers be 2x and 3x.
Then, their L.C.M = 6x. So, 6x = 48 or x = 8.
The numbers are 16 and 24.
Hence, required sum = (16 + 24) = 40.
Answer:C
The answer is: C
|
C
|
mathematics
|
If the sum of four consecutive positive integers is A, then the sum of the next four consecutive integers in terms of A is:
|
[
"A+4",
"A+16",
"2A",
"2A + 4",
"4A"
] |
In Case of Consecutive Integers or Integers in Arithmetic Progression Mean = Median
I.e. Median = A/4 = Mean = Average of Second and Third Integer
First Integer = A/4 - 1.5
Second Integer = A/4 - .5
Third Integer = A/4 + .5
Fourth Integer = A/4 + 1.5
i.e.
Fifth Integer = A/4 + 2.5
Sixth Integer = A/4 + 3.5
Seventh Integer = A/4 + 4.5
Eighth Integer = A/4 + 5.5
Now Mean of next 4 Integers = Median = A/4 + 4
i.e. Sum of Next 4 integers = (A/4 + 4)*4 = A+16
Answer: option B
The answer is: B
|
B
|
mathematics
|
Mary received a 20% raise each month for three consecutive months. What was her salary after the three raises if her starting salary was $1,000 per month?
|
[
"$1,348",
"$1,500",
"$1,631",
"$1,728",
"$1,863"
] |
1000 * 1.2 * 1.2 * 1.2 = 1000 * 1.728 = 1728
Answer: D
The answer is: D
|
D
|
mathematics
|
A father was as old as his son's present at the time of your birth. If the father's age is 42 years now, the son's age 5years back was?
|
[
"10 years",
"12 years",
"14 years",
"16 years",
"20 years"
] |
Let the son's present age be x years. Then, (42 - x) = x
2x = 42.
x = 21.
Son's age 5 years back (21 - 5) = 16 years.
D
The answer is: D
|
D
|
mathematics
|
How many different pairs of numbers (s, t) such that s = 3t can be obtained if s and t are selected from the set of number {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
|
[
"1",
"2",
"3",
"4",
"5"
] |
s = 3t.
So, s/3 = t
That means s is divisible by 3.
Only 0, 3, 6, 9 are divisible by 3.
Hence option (D).
The answer is: D
|
D
|
mathematics
|
If two letters are taken at random from the word HOME, what is the probability that none of the letters would be vowels?
|
[
"1/6",
"1/9",
"8",
"2/2",
"1/1"
] |
Answer: A) 1/6
The answer is: A
|
A
|
mathematics
|
The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is?
|
[
"767 m",
"467 m",
"245 m",
"567 m",
"544 m"
] |
Speed = [45 X 5/18] m/sec = [25/2] m/sec Time
= 30 sec Let the length of bridge be x metres. Then, (130 + x)/30 = 25/2
=> 2(130 + x) = 750 => x = 245 m.
Answer:C
The answer is: C
|
C
|
mathematics
|
5358 x 71 = ?
|
[
"273762",
"283758",
"383298",
"273258",
"380418"
] |
E
5358 x 71 = 5358 x (70 + 1)
= 5358 x 50 + 5358 x 1
= 375060 + 5358
= 380418
The answer is: E
|
E
|
mathematics
|
A person can swim in still water at 10 km/h. If the speed of water 4 km/h, how many hours will the man take to swim back against the current for 12 km?
|
[
"2",
"7",
"5",
"9",
"6"
] |
M = 10
S = 4
US =10 - 4 = 6
D = 12
T = 12/6 = 2
Answer: A
The answer is: A
|
A
|
mathematics
|
Replace the ? mark with an appropriate approximate value in the following equation’?
2 4/3 of 165.83+25% of 1847= ? - 554.7
|
[
"1563.22",
"1568.22",
"179.22",
"15659.22",
"1569.22"
] |
2 4/3 of 165.83+25% of 1847= ? - 554.7
10/3 of 165.83+25/100 of 1847= ? - 554.7
552.77+461.75= ? - 554.7
552.77+461.75 + 554.7= ?
≈ 1569.22
Answer E
The answer is: E
|
E
|
mathematics
|
By selling a house for Rs.45000, it was found that 1/8 of the outlay was gained, what ought the selling to price to have been in order to have lost 5 p.c?
|
[
"38008",
"38000",
"38005",
"38001",
"38002"
] |
CP + CP/8 = 45000
CP = 40000
SP = 40000*(95/100) = 38000
Answer: B
The answer is: B
|
B
|
mathematics
|
Taylor is making a bracelet. He Starts with 2 blue knots, 6 red knots, and 2 yellow knots, in that order, and repeats the pattern until there is no more string. If the last Knot is yellow which of the following could be the total number of knots on the bracelet.
|
[
"89",
"79",
"95",
"97",
"102"
] |
Repeating sequence = 2 + 6 + 2 = 10.
As the pattern ends in Y this could be the 9th thread or 10 thread (both are yellow)
Out of the answer choices, correct on should be a multiple of 10(since 10 threads are repeating) and if not, multiple of 10 + 9 (since 10 threads are repeating and last sequence end at first yellow)
none of the options is a direct multiple of 10 and only option that is multiple of 10; + 9 is 79 (10*7) + 9
Hence, answer is B
The answer is: B
|
B
|
mathematics
|
How many of the following numbers are divisible by 132 ?
264, 396, 462, 792, 968, 2178, 5184, 6336
|
[
"3",
"4",
"6",
"7",
"8"
] |
132 = 4 x 3 x 11
So, if the number divisible by all the three number 4, 3 and 11, then the number is divisible by 132 also.
264 11,3,4 (/)
396 11,3,4 (/)
462 11,3 (X)
792 11,3,4 (/)
968 11,4 (X)
2178 11,3 (X)
5184 3,4 (X)
6336 11,3,4 (/)
Therefore the following numbers are divisible by 132 : 264, 396, 792 and 6336.
Required number of number = 4.
B)
The answer is: B
|
B
|
mathematics
|
Mayank Bothra purchased 20 dozens of toys at the rate of 375 Rs per dozen .He sold each one of them at the rate of Rs 33.What was his percentage profit?
|
[
"5.6 %",
"6.5 %",
"7.5 %",
"7.6 %",
"None"
] |
Sol.
Cost = 375 * 20 = 7500
sale price 33 * 20 * 12
= 7920 profit = 420 profit in % = 420/7500 * 100 =5.6 %
Ans: A.
The answer is: A
|
A
|
mathematics
|
In how many different number of ways 3 boys and 2 girls can sit on a bench?
|
[
"700",
"710",
"120",
"720",
"740"
] |
npn = n!
5p5 = 5 × 4 × 3 × 2 × 1 = 120
C
The answer is: C
|
C
|
mathematics
|
In a village there are 150 men and 90 women in present time.if in next year population will be P=(a^2 +b^2)^1/2 , and in every year men are reduces 6%.what is population of after 2 year.
|
[
"140",
"141",
"142",
"143",
"145"
] |
next year total population=[150^2+90^2]^.5=174.92=175
man decreased by 6% so total man =150*.94=141
women will be= 175-141=34
so population after two years= [135^2+34^2]^.5=145.04=145
so population after two year= 145
ANSWER:E
The answer is: E
|
E
|
mathematics
|
Mike took a taxi to the airport and paid $2.50 to start plus $0.25 per mile. Annie took a different route to the airport and paid $2.50 plus $5.00 in bridge toll fees plus $0.25 per mile. If each was charged exactly the same amount, and Annie's ride was 22 miles, how many miles was Mike's ride?
|
[
"30",
"36",
"42",
"48",
"54"
] |
The cost of Annie's ride was 2.5+5+(0.25*22) = $13
Let x be the distance of Mike's ride.
The cost of Mike's ride is 2.5+(0.25*x) = 13
0.25*x = 10.5
x = 42 miles
The answer is C.
The answer is: C
|
C
|
mathematics
|
Mary and Joe are to throw three dice each. The score is the sum of points on all three dice. If Mary scores 10 in her attempt what is the probability that Joe will outscore Mary in his?
|
[
"24/64",
"32/64",
"36/64",
"40/64",
"42/64"
] |
Expected value of one die is 1/6*(1+2+3+4+5+6)=3.5.
Expected value of three dice is 3*3.5=10.5.
Mary scored 10 so the probability to get the sum more then 10 (11, 12, 13, ..., 18), or more then the average, is the same as to get the sum less than average (10, 9, 8, ..., 3) = 1/2 = 32/64.
That's because the probability distribution is symmetrical for this case:
The probability of getting the sum of 3 (min possible sum) = the probability of getting the sum of 18 (max possible sum);
The probability of getting the sum of 4 = the probability of getting the sum of 17;
The probability of getting the sum of 5 = the probability of getting the sum of 16;
...
The probability of getting the sum of 10 = the probability of getting the sum of 11;
Thus the probability of getting the sum from 3 to 10 = the probability of getting the sum from 11 to 18 = 1/2.
Answer: B.
The answer is: B
|
B
|
mathematics
|
The average height of 30 girls out of a class of 40 is 160 cm. and that of the remaining girls is 156 cm. The average height of the whole class is :
|
[
"158 cms",
"158.5 cms",
"159 cms",
"159.5 cms",
"none"
] |
Explanation:
Average height of the whole class =(36×160+10×156/40)=159 cms
Answer C
The answer is: C
|
C
|
mathematics
|
Vinoth can complete a painting work in 20 days. Prakash can do the same work in 25 days. They start the work together but Vinoth quit after 3 days of work. How many days are required to complete the remaining painting work by Prakash.
|
[
"15.25 days",
"16.25 days",
"17.25 days",
"18.25 days",
"19.25 days"
] |
Vinoth can complete the painting work in one day is 1/20
Prakash can complete the same work in one day is 1/25
Both of them can complete the work in 1/20+ days=9/100( 1/20+1/25)
they must have completed in three days=9/100*3=27/100
Remaining work to be done is by Prakash =1-27/100=73/100
For one work, Prakash can do in 25 days
For 73/100 work, he can do in 73/100*25=73/4days or 18.25 days
ANSWER:D
The answer is: D
|
D
|
mathematics
|
In a parallelogram, the length of one diagonal and the perpendicular dropped on that diagonal are 30 and 20 metres respectively. Find its area
|
[
"600 m2",
"540 m2",
"680 m2",
"574 m2",
"None of these"
] |
In a parallelogram.
Area = Diagonal × length of perpendicular on it.
= 30 × 20 = 600 m2
Answer A
The answer is: A
|
A
|
mathematics
|
What are the last two digits of (301*402*503*604*646*547*449*349)^2
|
[
"96",
"76",
"56",
"36",
"24"
] |
((301*402*503*604*646)*(547*449*349))^2
If you observe above digits, last digit are: 1,2,3,4,6,7,9,9; 5&9 are missing; so I have rearranged them so that multiplication will be easy for me as initial 4 digits have last two digits as 01,02,03,04,46 and final three as 47*49*49.
Solving for only last two digits and multiplying them we get:( (06*04*46)(47*01))^2 = (44*47)^2=68^2=24
Hence answer is E
The answer is: E
|
E
|
mathematics
|
If x is an integer, then x(x – 1)(x – k) must be evenly divisible by three when k is any of the following values EXCEPT
|
[
"-4",
"-2",
"-1",
"2",
"5"
] |
There is probably an easier way, but I just used the picking numbers option for this.
I chose x=2
2(1)(2-k) then just plugged in the answer choices for K until one wasn't evenly divisible by 3.
B gives you 8. 8/3 is not an integer.
B is the answer
The answer is: B
|
B
|
mathematics
|
Set M contains numbers that satisfy the condition that, if integer x is in the set then x-3 will also be in the set M. If -4 is one of the value in the set, which of the following numbers must also be present in the set M.
I.-7
II. -1
III. 2
|
[
"I only",
"II only",
"I and II only",
"II and III only",
"I, II and III"
] |
Notice that we are askedwhich of the following numbers MUST also be present in the set MnotCOULD be in the set.
Now, if -4 is in the set, then -4-3=-7mustbe in the set. Could -1 or 2 be in the set? Certainly, but we don't know that for sure.
Answer: A.
The answer is: A
|
A
|
mathematics
|
Ray writes a two digit number. He sees that the number exceeds 4 times the sum of its digits by 3. If the number is increased by 18, the result is the same as the number formed by reversing the digits. Find the number.
|
[
"2",
"5",
"6",
"7",
"8"
] |
Solution: Let the two digit number be xy.
4(x + y) +3 = 10x + y .......(1)
10x + y + 18 = 10 y + x ....(2)
Solving 1st equation we get 2x - y = 1 .....(3)
Solving 2nd equation we get y - x = 2 .....(4)
Solving 3 and 4, we get x = 3 and y = 5
Answer:B
The answer is: B
|
B
|
mathematics
|
The cost price of an article is 64% of the marked price. Calculate the gain percent after allowing a discount of 12%.
|
[
"37.5 %",
"38.5 %",
"42 %",
"27.5 %",
"none"
] |
Sol.
Let marked price = Rs. 100. Then, C.P. = Rs. 64. S.P = Rs. 88.
∴ Gain % = [24/64 * 100]% = 37.5%.
Answer A
The answer is: A
|
A
|
mathematics
|
My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?
|
[
"70",
"69",
"82",
"89",
"72"
] |
Let m be my age in years. If s is my son's age in years, then my son is 52s weeks old. If g is my grandson's age in years, then my grandson is 365g days old. Thus,
365g = 52s.
Since my grandson is 12g months old,
12g = m.
Since my grandson, my son and I together are 120 years,
g + s + m = 120.
The above system of 3 equations in 3 unknowns (g, s and m) can be solved as follows.
m / 12 + 365 m / (52 x 12) + m = 120 or
52 m + 365 m + 624 m = 624 x 120 or
m = 624 x 120 / 1041 = 72.
The answer is: E
|
E
|
mathematics
|
Pump A can fill a tank of water in 5 hours. Pump B can fill the same tank in 8 hours. How long does it take the two pumps working together to fill the tank?(round your answer to the nearest minute).
|
[
"2 hours 2 minutes",
"3 hours 5 minutes",
"4 hours 6minutes",
"5 hours 7 minutes",
"7 hours 9 minutes"
] |
In 1 hour pump A can fill 1/5 of a tank and pump B can fill 1/8 of the same tank. So in 1 hour the two pumps working together can fill
1/5 + 1/8 = 13 / 40 of a tank
Since the rate of the two pumps working together is 13/40, the time t needed to fill the tank by the two pumps is found by solving
(13/40) t = 1
t = 40 / 13 = 39/13 + 1/13 hours
= 3 hours and (1/13)*60 minutes
= 3 hours 5 minutes (rounded to the nearest minute)
correct answer B
The answer is: B
|
B
|
mathematics
|
A student was asked to find the arithmetic mean of the numbers 3, 11, 7, 9, 15, 13, 8, 19, 17, 21, 14 and x. He found the mean to be 12. What should be the number in place of x ?
|
[
"8",
"7",
"6",
"5",
"4"
] |
Clearly, we have (3 + 11 + 7 + 9 + 15 + 13 + 8 + 19 + 17 + 21 + 14 + x) / 12 = 12.
or 137 + x = 144 o144 - 137 = 7.
Answer: B
The answer is: B
|
B
|
mathematics
|
By selling 150 mangoes, a fruit-seller gains the selling price of 15 mangoes. Find the gain percent?
|
[
"27%",
"25%",
"11%",
"85%",
"24%"
] |
SP = CP + g
150 SP = 150 CP + 15 SP
135 SP = 150 CP
135 --- 15 CP
100 --- ? => 11%
Answer:C
The answer is: C
|
C
|
mathematics
|
Two bus tickets from city A to B and three tickets from city A to C cost Rs. 77 but three tickets from city A to B and two tickets from city A to C cost Rs. 73. What are the fares for cities B and C from A ?
|
[
"11",
"13",
"44",
"55",
"61"
] |
Explanation:
Let Rs. x be the fare of city B from city A and Rs. y be the fare of city C from city A. Then, 2x + 3y = 77 ...(i) and 3x + 2y = 73 ...(ii) Multiplying (i) by 3 and (ii) by 2 and subtracting, we get: 5y = 85 or y = 17. Putting y = 17 in (i), we get: x = 13.
Answer: B
The answer is: B
|
B
|
mathematics
|
A man, a woman and a boy can complete a job in 3, 4 and 12 days respectively. How many boys must assist 1 man and 1 woman to complete the job in 1/4 of a day?
|
[
"22",
"66",
"28",
"41",
"61"
] |
(1 man + 1 woman)'s 1 day work = (1/3 + 1/4) = 7/12 Work done by 1 man and 1 woman in 1/4 day = (7/12 * 1/4) = 7/48
Remaining work = (1 - 7/48) = 41/48
Work done by 1 boy in 1/4 day = ( 1/12 * 1/4) = 1/48
Number of boys required = 41/48 * 41 = 41.
Answer: D
The answer is: D
|
D
|
mathematics
|
If two dice are thrown together, the probability of getting an even number on one die and an odd number on the other is?
|
[
"1/8",
"1/2",
"4/2",
"1/9",
"7/2"
] |
The number of exhaustive outcomes is 36.
Let E be the event of getting an even number on one die and an odd number on the other. Let the event of getting either both even or both odd then
= 18/36 = 1/2
P(E) = 1 - 1/2 = 1/2.
Answer: B
The answer is: B
|
B
|
mathematics
|
We have 36kg flour and 60kg sugar in stock and we would like to use the minimum number of packs that would have the same weight for both flour and sugar. How much more sugar is required if we would like to full 10 packs either of flour or sugar?
|
[
"12",
"18",
"20",
"24",
"30"
] |
k is the integer that represents kg of pack
ak = 36 --> k = 36/a
bk = 60 --> k = 60/b
36/a = 60/b --> 5a = 3b and then k=12 for min(a+b)
a=36/12=3 , b=60/12=5
Total number of packs = 3+5 = 8
10-8=2 packs more required
2 *12 = 24 kg more sugar required to have 10 packs.
ANSWER: D
The answer is: D
|
D
|
mathematics
|
If 85% of 3/5 of a number is 36, then the number is?
|
[
"80",
"100",
"70.5",
"90",
"None of these"
] |
Let the number be x. Then 85% of 3/5 of x=36
85/100*3/5*x=36
x=(36*100/51)=70.5
Required number=70.5.
Correct Option: C
The answer is: C
|
C
|
mathematics
|
If books bought at prices ranging from Rs. 200 to Rs. 350 are sold at prices ranging from Rs. 300 to Rs. 425, what is the greatest possible profit that might be made in selling eight books ?
|
[
"23267",
"2677",
"1800",
"2778",
"76611"
] |
Explanation:
Least Cost Price = Rs. (200 * 8) = Rs. 1600.
Greatest Selling Price = Rs. (425 * 8) = Rs. 3400.
Required profit = Rs. (3400 - 1600) = Rs. 1800.
Answer: C) 1800
The answer is: C
|
C
|
mathematics
|
a spider web consists of 3 concurrent lines forming radial support for 20 concentric regular hexagon .the hexagon vertices are 5mm from their immidiate neighbour. if the innermost hexagon has a side length 3mm how many meters is the length of the entire web including the 3 diagonals ?
|
[
"7.354 m",
"8.354 m",
"6.354 m",
"9.354 m",
"5.354 m"
] |
for perimeter of all hexagon =6*(3+8+13+...........20th term.)
sum will be 6060 mm
and for length of one diagonal find 20th term=98
so total length =6060+294=6354 mm=6.354 m
ANSWER:C
The answer is: C
|
C
|
mathematics
|
Consider below info to be a table:
AMOUNT OF BACTERIA
TIME - AMOUNT
1PM - 10gms
4PM - x gms
7PM - 22.5 gms
Data for a certain biology experiment are given in the table above. If the amount of bacteria present increased by the same factor during each of the two 3-hour periods shown, how many grams of bacteria were present at 4PM ?
|
[
"15.0",
"12.1",
"12.2",
"12.3",
"12.4"
] |
let say the factor is x, the at 7PM quantity = 10 (i.e. quantity @1PM)* x^2 =22.5 => x^2 =2.25 or x = 1.5 => @4PM quantity = 10x =10*1.5 =15.
Answer A
The answer is: A
|
A
|
mathematics
|
A bus travels k miles in n hours. How many miles will it travel in x hours at the same rate?
|
[
"knx",
"k⁄n",
"x",
"kx⁄n",
"kn⁄x"
] |
Given Speed = k/n
To Find distance in x hours with same speed
Distance = speed * time
Distance = k/n*x = kx/n
Answer D
The answer is: D
|
D
|
mathematics
|
A certain list consists of 21 different numbers. If n is in the list and n is 4 times the average(arithmetic mean) of the other 20 numbers in the list, then n is what fraction W of the sum of the 21 numbers in the list?
|
[
"1/20",
"1/6",
"1/5",
"4/21",
"5/21"
] |
This is how I used to calculate which I think works pretty well:
if you let the average of the 20 other numbers equal a, can you write this equation for sum of the list (S)
n + 20a = S
the question tells us that
n = 4a
plug this back into the first equation and you get that the sum is 24a
4a + 20a = 24a
therefore fraction W of n to the total would be
4a/24a or 1/6
answer B
The answer is: B
|
B
|
mathematics
|
The cost price of a radio is Rs.4800 and it was sold for Rs.4400, find the loss %?
|
[
"8",
"9",
"7",
"6",
"4"
] |
4800 ---- 400
100 ---- ? => 8%
Answer: A
The answer is: A
|
A
|
mathematics
|
In how many different ways can 3 identical green boots and 3 identical red boots be distributed among 6 people such that each person receives a pair of boots?
|
[
"7209",
"4059659",
"2169",
"20",
"7291"
] |
How to solve:
1st Person: 6 has options
2nd Person: 5 has options…
Therefore, for all people: 6 x 5 x 4 x 3 x 2 = 720 arrangements.
Since the reds are identical, we divide by 3! Since the greens are identical, we divide by another 3!
So: in all, 720/[ 3! X 3! ] = 20 ways.
(e.g. Answer: D)
The answer is: D
|
D
|
mathematics
|
If a radio is purchased for Rs 490 and sold for Rs 465.50 Find the loss%?
|
[
"3%",
"4%",
"5 percent",
"6%",
"None of these"
] |
Explanation :
Loss = 490 – 465.5 = 24.5 loss in % = 24.5/ 490 x 100 = 5%.
Answer : C
The answer is: C
|
C
|
mathematics
|
If a supermarket shows $49 of sales for apples, and on that same day there are sales of $64 in oranges. What is the ratio of sales for apples to oranges?
|
[
"1 : 2",
"2 : 3",
"4 : 7",
"1 : 5",
"None"
] |
Solution
Let us name the apples
as A and the oranges as B. = (A'S sales) : (B's sales)
=√b : √a
= √49 : √64
= 7 : 8
Answer E
The answer is: E
|
E
|
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