RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: A fair coin is tossed 11 times. What is the probability of getting more heads than tails in 11 tosses?
A.1/2
B.63/128
C.4/7
D.61/256
Answer: A.1/2
Explanation: On each toss, the probability of getting a head is 1/2 and the probability of getting a tail is 1/2.
There is no way to get the same number of heads and tails on an odd number of tosses.
There will either be more heads or more tails.
Then there must be more heads on half of the possible outcomes and more tails on half of the possible outcomes.
P(more heads) = 1/2
The answer is A.
Question: If three numbers are randomly selected without replacement from set {1, 2, 3}, what is the probability that the numbers are selected in ascending order?
A.1/6
B.1/4
C.1/8
D.1/24
Answer: A.1/6
Explanation: The total number of ways to arrange 3 numbers is 3! = 6.
There is only one way to arrange the numbers in ascending order.
P(ascending order) = 1/6
The answer is A.
Question: The ratio of the volumes of a cube to that of the sphere which will fit inside the cube is?
A.6.862kg
B.6.838 kg
C.6.632 kg
D.6.832 kg
Answer: D.6.832 kg
Explanation: 52 * 40 * 29 = 60320
48 * 36 * 27 = 46650
------------
13664
13664 * 1/2 = 6832 => 6.832 kg
Answer:D
Question: Four cups of milk are to be poured into a 3-cup bottle and a 4-cup bottle. If each bottle is to be filled to the same fraction of its capacity, how many cups of milk should be poured into the 4-cup bottle?
A. 2/3
B. 7/3
C. 5/7
D. 16/7
Answer: D. 16/7
Explanation: Let x be the # of cups going into the 4 cup bottle.
so.... x/4 = ((4-x)/3)
16 - 4x = 3x
16 = 7x
x = 16/7.
Answer : D.
Question: The average of first four prime numbers greater than 10 is?
A.10
B.20
C.15
D.40
Answer: C.15
Explanation: 11 + 13 + 17 + 19 = 60/4 = 15
ANSWER:C
Question: At what rate percent on simple interest will a sum of money double itself in 30 years?
A.3 1/3%
B.3 1/8%
C.3 6/3%
D.9 1/3%
Answer: A.3 1/3%
Explanation: P = (P*30*R)/100
R = 3 1/3%
Answer: A
Question: The probability that A speaks truth is 3/5 and that of B speaking truth is 4/7. What is the probability that they agree in stating the same fact?
A.18/35
B.18/38
C.18/34
D.18/31
Answer: A.18/35
Explanation: If both agree stating the same fact, either both of them speak truth of both speak false.
Probability = 3/5 * 4/7 + 2/5 * 3/7
= 12/35 + 6/35 = 18/35.
Answer:A
Question: John walking at 4 Kmph reaches his office 8 minutes late. If he walks at 6 Kmph, he reaches there 8 minutes earlier. How far is the office from his house?
A.3 1/5 Km
B.3 Km
C.4 1/5 Km
D.3 2/5 Km
Answer: A.3 1/5 Km
Explanation: Formula = S1*S2/S2-S1 * T1+T2/60
= 4*6/2 * 16/6
= 24/2 * 16/60
= 8 * 2/5
= 16/5 = 3 1/5 Km
A
Question: How many words with or without meaning, can be formed by using all the letters of the word, DELHI using each letter exactly once?
A.100
B.110
C.120
D.130
Answer: C.120
Explanation: DELHI=5 letters
5! ways =5p5=5*4*3*2*1=120 ways
ANSWER:C
Question: The length of the bridge, which a train 180 metres long and travelling at 45 km/hr can cross in 30 seconds, is?
A.245
B.777
C.282
D.195
Answer: D.195
Explanation: Speed = [45 X 5/18] m/sec = [25/2] m/sec Time = 30 sec Let the length of bridge be x metres. Then, (180 + x)/30 = 25/2 => 2(180 + x) = 750 => x = 195 m.
Answer: D
Question: Find the area of trapezium whose parallel sides are 20 cm and 18 cm long, and the distance between them is 17 cm
A.178 cm2
B.323 cm2
C.285 cm2
D.167 cm2
Answer: B.323 cm2
Explanation: Area of a trapezium = 1/2 (sum of parallel sides) * (perpendicular distance between them)
= 1/2 (20 + 18) * (17)
= 323 cm2
Answer: B
Question: Some part of the 50% solution of acid was replaced with the equal amount of 30% solution of acid. As a result, 40% solution f acid was obtained. what part of the original solution was replaced?
A.1/5
B.1/4
C.1/2
D.3/4
Answer: C.1/2
Explanation: Let X = Part of acid solution replaced, then 1-X will be the parts not replaced.
(1-X)*0.5 + 0.3*x = 0.4
0.5 - 0.5X +0.3X = 0.4
-0.2X = -0.1
X=1/2
So the answer is C
Question: What will come in place of the x in the following Number series? 25, 100, x, 1600, 6400
A.6400
B.4346
C.5674
D.7674
Answer: A.6400
Explanation: (A)
25 x 4 = 100, 100 x 4 = 400, 400 x 4 = 1600, 1600 x 4 = 6400.
Question: In a car wheel, two spokes cover 15 degree. Then for the entire car,how many spokes are there?
A.92
B.128
C.192
D.208
Answer: C.192
Explanation: given, 2 spokes cover 15degrees,
so for 360 degrees.---->360*2/15=48..
so, for entire car, 4*48=192
ANSWER:C
Question: What is the perimeter of a triangle with sides 5 and 4 that has the maximum possible area?
A.9 + 3√2
B.9 + √41
C.16
D.9 + √37
Answer: B.9 + √41
Explanation: We can maximize the area of the triangle by making these two sides the base and the height of a right angle triangle. Then the third side is the hypotenuse with a length of √(25+16) = √41
The perimeter is 9 + √41
The answer is B.
Question: A palindrome is a number that reads the same forward and backward, such as 343. How many odd, 8-digit numbers are palindromes?
A.4000
B.4500
C.5055
D.5000
Answer: D.5000
Explanation: First recognize you only need to consider the first four digits (because the second four are just the first four flipped)
There are 9000 possibilities for the first four digits of a 8 digit number, 1000-9999 inclusive. Everything starting with a 1,3,5,7,9 will be odd, which is 5/9ths of the combinations.
5/9*9000 = 5000
ANSWER:D
Question: In a museum, the entrance ticket costs Rs. 250. In vacation, the cost of the ticket is reduced, there by increasing the sale by 50%. but it was found that the collection is decreased by 17.5%. What is the deduction in the ticket price?
A.Rs.100
B.Rs. 112.5
C.Rs. 110
D.Rs. 115.5
Answer: B.Rs. 112.5
Explanation: Let there is sell of 100 tickets.
So total Collection = 250 *100 = Rs. 25,000 [Price of one ticket = Rs. 100]
Now, Total ticket sale = 100 + 50 % of 100 = 150.
This effected 17.5% decrease in collection.
So, Collection after increased sale,
= 25000 - 17.5% of 25000 = Rs. 20, 625.
In vacation time per ticket price,
= 20625/150 = Rs. 137.5.
Decreased in each ticket price,
= 250 - 137.5 = Rs. 112.5.
ANSWER : OPTION B
Question: If, 3 years ago, Jamie was half as old as he is now, how old will he be in x years?
A.x + 10
B.x + 5
C.x + 2
D.x + 6
Answer: D.x + 6
Explanation: let his age be a. a-3=a/2 hence a=6. 6 years hence, a =x+6
Answer D
Question: Before a salary increase, the weekly salary of a worker for 42 hours in a week was as much as the worker is paid now for 35 hours of work in a week. What is the percent increase in the worker's salary per hour?
A.20
B.22
C.24
D.26
Answer: A.20
Explanation: Let x be the original salary per hour.
Let y be the salary per hour after the increase.
35y=42x
y=(42/35)x=1.2x
The salary increased 20%.
The answer is A.
Question: Tom reads at an average rate of 30 pages per hour, while Jan reads at an average rate of 39 pages per hour. If Tom starts reading a novel at 4:30, and Jan begins reading an identical copy of the same book at 5:06, at what time will they be reading the same page?
A.6:06
B.6:36
C.7:06
D.7:36
Answer: C.7:06
Explanation: Since Tom reads an average of 1 page every 2 minutes, Tom will read 18 pages in the first 36 minutes. Jan can catch Tom at a rate of 9 pages per hour, so it will take 2 hours to catch Tom.
The answer is C.
Question: m is a positive integer. m! is ending with k zeros, (m+2)! is ending with k+2 zeros. Find the number of possible values of m, if 90 ≤ m ≤ 190.
A.2
B.3
C.4
D.6
Answer: D.6
Explanation: Possible values of m where (m+2)! has two zeroes more than the no. of zeroes in m! are
m=98,99--No of zeroes 22 (m+2)! i.e, 100 and 101 have 24 zeroes each.
m=148,149
m=174,175
no. of possible values of m=6.
Answer has to be D.
Question: In how many ways can the letters of the word "MARS" be arranged?
A.16
B.20
C.24
D.28
Answer: C.24
Explanation: The total ways of arranging the letters = 4! = 24
The answer is C.
Question: A firm has 2 senior partners and 5 junior partners. How many different groups of 3 partners can be formed in which at least one member of the group is a senior partner? (Note that two groups are considered different if at least one group member is different.)
A.17
B.21
C.25
D.29
Answer: C.25
Explanation: The number of ways to form a group of 3 is 7C3 = 35
The number of groups with no senior partner is 5C3 = 10
The number of groups with at least one senior partner is 35-10 = 25
The answer is C.
Question: The average of 10 consecutive integers is 11. Then, 9 is deducted from the first consecutive number, 8 is deducted from the second, 7 is deducted form the third, and so on until the last number which remains unchanged. What is the new average?
A.5
B.5.5
C.6
D.6.5
Answer: D.6.5
Explanation: The total subtracted is (9+8+...+1) = (9*10) / 2 = 45
On average, each number will be reduced by 45/10 = 4.5
Therefore, the overall average will be reduced by 4.5
The answer is D.
Question: Calculate f(3), given that f(x) = x3 + f0(-1)x2 + f00(1)x + f0(-1)f(-1).
A.198
B.197
C.196
D.195
Answer: A.198
Explanation: Differentiating, we compute
f0(x) = 3x2 + 2f0(-1)x + f00(1)
f00(x) = 6x + 2f0(-1):
Plugging in x = -1 into the first equation and x = 1 into the second, we obtain a system of
equations in f0(-1) and f00(1):
f0(-1) = 3 - 2f0(-1) + f00(1);
f00(1) = 6 + 2f0(-1):
Denoting f0(-1) and f00(1) by a and b respectively, we have
a = 3 - 2a + b
b = 6 + 2a:
Plugging the second equation into the first, we get
a = 3 - 2a + (6 + 2a) = 9:
Thus, b = 6 + 2a = 24, so
f(x) = x3 + ax2 + bx + af(-1) = x3 + 9x2 + 24x + 9f(-1):
Finally, plugging x = -􀀀1 into this equation, we get
f(-1) =-1 + 9-24 + 9f(-1)
-8f(-1) = -16
f(-1) = -2
We conclude that
f(x) = x3 + 9x2 + 24x + 18
f(3) = 33 + 9* 32 + 24 *3 + 18
= 27 + 81 + 72 + 18 = 198
correct answer A
Question: A man can row upstream at 4kmph and downstream at 10 kmph. The speed of the stream is
A.2.5 km/hr
B.4.2 km/hr
C.3 km/hr
D.10.5 km/hr
Answer: C.3 km/hr
Explanation: Sol.
Speed of stream = 1/2(10 -4) kmph = 3 kmph.
Answer C
Question: A motorist covers a distance of 39km in 45min by moving at a speed of x kmph for the first 15min, then moving at double the speed for the next 20 min, and then again moving at his original speed for the rest of the journey. Find x.
A.60 km/h
B.48 km/h
C.36 km/h
D.58 km/h
Answer: C.36 km/h
Explanation: Total distance = 39 km
Total time = 45 min
D = S*T
x * 15/60 + 2x * 20/60 + x * 10/60 = 39 km
x = 36 kmph
Answer : C.
Question: A sells to B goods at five-thirds the rate of profit at which B has decided to sell it to C. C, on other hand sells it to D at one-third the rate of profit at which B sold it to C. If D gives Rs. 2145 to C at 10%, how much did A buy it for ?
A.1000
B.1100
C.1200
D.1300
Answer: A.1000
Explanation: let profit rate of b = x
acc to question profit rate of a becomes 5/3 x
and that of c= 1/3 x which is given as 10%
1/3 x= 10
therefore x=30
now b=30% , a=50%
now we will find out c's price-
11/10 * price = 2145
price = 1950
in similar way we will find out b's price as we know that profit is 30%
therefore 130/100 * price = 1950
so b 's price =1500
similarly for a ('profit is 50%)
150/100 * price = 1500
on solving it we get
a's price = 1000
ANSWER:A
Question: Sagar was riding bike towards north,turned left road 1 km turnes towrds left &road 2km found himself 1km west of starting how far did he road north?
A.2km in north.
B.2km in south.
C.2km in east.
D.2km in west.
Answer: A.2km in north.
Explanation: He travelled total distance of 3km.
From which he travelled 1km in west.
Hence in all he travelled total 2km in north.
ANSWER:A
Question: Sum of the squares of three numbers is 138 and the sum of their products taken two at a time is 131. Find the sum?
A.20
B.21
C.23
D.25
Answer: A.20
Explanation: (a + b + c)2 = a2 + b2 + c2 + 2(ab +bc + ca) = 138 + 2* 131
a + b + c = √400 = 20
A
Question: Which of the following ranges of numbers includes the greatest number of prime numbers?
A.10-19, inclusive
B.20-29, inclusive
C.40-49, inclusive
D.60-69, inclusive
Answer: A.10-19, inclusive
Explanation: Prime numbers between -
A. 10-19, inclusive is 4 (11 , 13 , 17 , 19)
B. 20-29, inclusive is 2 ( 23, 29)
C. 40-49, inclusive is 3 ( 41 , 43 , 47)
D. 60-69, inclusive is 2 ( 61, 67)
E. 70-79, inclusive is 3 ( 71, 73, 79)
Thus A. 10-19, inclusive contains greatest number of prime numbers.
ANSWER:A
Question: A man takes 3 hours 45 minutes to row a boat 15 km downstream of a river and 2hours30minutes to cover a distance of 5km upstream. find the speed of the river current in km/hr.
A.2km/hr
B.1km/hr
C.5km/hr
D.2m/hr
Answer: B.1km/hr
Explanation: rate downstream=(15/3 ¾)km/hr=(15*4/15)km/hr=4km/hr.
Rate upstream=(5/2 ½)km/hr=(5*2/5)km/hr=2km/hr.
Speed of current=1/2(4-2)km/hr=1km/hr
Answer is B.
Question: If the terms of a series are either2or24and the sum of all the terms D of the series is 124, then which of the following could be the number of2sin the series?
A.26
B.29
C.35
D.40
Answer: A.26
Explanation: Ans: A
Solution: we are not certain how many 2 or 24 are there. but as given sum of all the terms is 124 means 24*5= 120 so number of 24 can't be more than 5
so D=24x +2y = 124
24*5 + 2y =124 then y=2
24*4 + 2y = 124 then y=14
24*3 +2y = 124 then y= 26
24*2 +2y =124 then y = 38
24 +2y = 124 then y= 50
26 is the ans.A
Question: The distance between X&Y is 400km. A person is traveling from X to Y at 60km/hr started at 11AM and another person is traveling from Y to X at 40km/hr and started at same time. Then at what time they meet together.?
A.A)2PM
B.B)4PM
C.C)1PM
D.D)3PM
Answer: D.D)3PM
Explanation: Let x hours be they will meet together
distance covered by 1st person+distance covered by 2nd person = 400km
60x+40x = 400
x= 4 hr
They will meet = 11AM +4hr = 3PM
Answer is D
Question: If a quarter kg of potato costs 60 yen, how many paise will 200 gm cost?
A.yen 48
B.yen 54
C.yen 56
D.yen 72
Answer: A.yen 48
Explanation: Explanation: Let the required weight be x kg.
Less weight, Less cost (Direct Proportion)
250 : 200 :: 60 : x 250 x x = (200 x 60)
x= (200 x 60)/250
x = 48
Answer: Option A
Question: The ratio of numbers is 3:4 and their H.C.F is 4. Their L.C.M is:
A.12
B.16
C.24
D.48
Answer: D.48
Explanation: Let the numbers be 3x and 4x.
Then their H.C.F = x. So, x = 4.
So, the numbers are 12 and 16.
L.C.M of 12 and 16 = 48.
ANSWER:D
Question: Find the mean proportional between 7921 & 9409?
A.8163
B.8633
C.8663
D.8636
Answer: B.8633
Explanation: Explanation:
Formula = √a×b
A = 7921 and B = 9409
√7921×9409 = 89 × 97 = 8633
Answer: Option B
Question: 0---:-|---:--|-:--:-|--:---|-:----1
On the number line above, the segment from 0 to 1 has been divided into fifths, as indicated by the large tick marks, and also into sevenths, as indicated by the small tick marks. What is the LEAST possible distance Z between any two of the tick marks?
A.1/70
B.1/35
C.2/35
D.1/12
Answer: B.1/35
Explanation: divisions are 0 1/7 2/7 3/7 4/7 5/7 6/7 1
1/5 2/5 3/5 4/5 5/5
expressing the same in terms of the lcm of 5,7 ,i.e 35
0 7/35 14/35 21/35 28/35 35/35
5/35 10/35 15/35 20/35 25/35 30/35
by comparing the divisions with each other we can see 1/35 is the shortest possible distance between any two selected divisions.
Z=1/35
Answer is B.
Question: Find the product of the local value and absolute value of 8 in 564823
A.1600
B.6400
C.16000
D.12000
Answer: B.6400
Explanation: Explanation:
Place value = Local value
Face value = Absolute value
The place value of 8 in 564823 is 8 x 100 = 800
The face value of 8 in 564823 is nothing but 8.
=> 800*8=6400
Answer: Option B
Question: In a certain city, 80 percent of the households have cable television, and 50 percent of the households have videocassette recorders. If there are 150,000 households in the city, then the number of households that have both cable television and videocassette recorders could be any number from:
A.45,000 to 90,000 inclusive
B.30,000 to 120,000 inclusive
C.45,000 to 75,000 inclusive
D.75,000 to 120,000 inclusive
Answer: C.45,000 to 75,000 inclusive
Explanation: The maximum percentage with both is 50% which is 75,000 households.
This means that every household with a recorder also has cable television.
The minimum percentage with both is 30% which is 45,000 households.
This means that 20% of households have only recorders but not cable television.
The other 30% of households with recorders have cable television.
The answer is C.
Question: A thief goes away with a SANTRO car at a speed of 25 kmph. The theft has been discovered after half an hour and the owner sets off in a bike at 50 kmph when will the owner over take the thief from the start?
A.5/3 hours
B.2/7 hours
C.1 hours
D.3 hours
Answer: C.1 hours
Explanation: -----------25--------------------|
50 25
D = 25
RS = 50 â€“ 25 = 25
T = 25/25 = 1 hours
ANSWER:C
Question: how many 1x1x1 cubes can you fit in a 15x16x13 box?
A.3,200
B.3,150
C.3,448
D.3,120
Answer: D.3,120
Explanation: The answer is D) 3,120. A 1x1x1 cube has an area of 1. The 15x16x13 box has an area of 3,120. If you divide 3,120 by 1, you get 3,120. Therefore the answer is D.
Question: At a certain rate of simple interest per annum the amount due in 3 & 1/2 yrs and 5 & 1/2 yrs are respectively Rs4560 & Rs4840. Find the rate of Simple Interest ?
A.1.43
B.4.43
C.2.43
D.3.43
Answer: D.3.43
Explanation: let the amount p & rate r
now 4560-p=(p*r*7/2)/100 .....(1)
4840-p=(p*r*11/2)/100 .....(2)
by solving the eq. we get the p=4070 and r=3.43
so the ans is 3.43
ANSWER:D
Question: A train 800 m long is running at a speed of 78 km/hr. If it crosses a tunnel in 1 min, then the length of the tunnel is?
A.130 m
B.360 m
C.500 m
D.540 m
Answer: C.500 m
Explanation: Speed = 78 * 5/18 = 65/3 m/sec.
Time = 1 min = 60 sec.
Let the length of the train be x meters.
Then, (800 + x)/60 = 65/3
x = 500 m.
ANSWER:C
Question: A trained covered x km at 65 kmph and another 2x km at 20 kmph. Find the average speed of the train in covering the entire 3x km.
A.22
B.99
C.26
D.66
Answer: C.26
Explanation: Total time taken = x/65 + 2x/20 hours
= 3x/26 hours
Average speed = 3x/(3x/26) = 26 kmph
Answer: C
Question: A set of 11 positive integers has an average of 35. Which of the following is the greatest possible value for the median of this set?
A.64
B.30
C.36
D.45
Answer: A.64
Explanation: for the median to be max , we should take all the values below meadian to be the lowest and the remaining values to be the same..
here 1 is the lowest value(positive int) so the lowest 5 int will equal 5..
remaining 6= 35*11-5=380..
therefore each valueof these 6 int =380/6=64
ans A
Question: The sum of the non-prime numbers between 60 and 70, non-inclusive, is
A.387
B.429
C.457
D.499
Answer: C.457
Explanation: sum of consecutive integers from 61 to 69, inclusive ====> (A1 + An)/2 * # of terms = (61 + 69)/2 * 9 = 65 *9 = 585
sum of non-prime numbers b/w 60 and 70, non inclusive ===> 585 - 128 (i.e., 61 + 67, being the prime #s in the range) =457
Answer: C
Question: If S is the sum of the reciprocals of the consecutive integers from 81 to 90, inclusive, which of the following is less than S?
I. 1/8
II. 1/9
III. 1/10
IV. 1/5
V. 1/8>S >1/9
A.V
B.I
C.II
D.III
Answer: A.V
Explanation: Since we summarize the reciprocals from 90 to 81, we can say also that we add ten numbers who are all (with one exception 1/90) greater than 1/90, so that the sum must be greater than 1/9.
On the other side we can say that we add the reciprocals from 91 to 100, so that the sum has to be less than the sum of ten times 1/91.
sum has to be greater than 1/9 and less than 1/8
A
Question: A thief is spotted by a policeman from a distance of 200metres. When the policeman starts the chase, the thief also starts running. If the speed of the thief be 18km/hr and that of the policeman 22km/hr, how far the thief will have run before he is overtaken ?
A.A)900m
B.B)500m
C.C)650m
D.D)750m
Answer: A.A)900m
Explanation: Relative speed of the policeman = 22-18 = 4 km/hr
time taken by policeman to cover 200m = (200/1000)*(1/4) = 1/20 hr
In 1/20 hr the thief covers a distance of 18/20 km = 9/10 km = 900m
Answer is A
Question: A contest will consist of n questions, each of which is to be answered eithertrueorfalse. anyone who answers all n questions correctly will be a winner. what is the least value of n for which the probability is less than 1/500 that a person who randomly guesses the answer to each question will be a winner?
A.5
B.10
C.50
D.100
Answer: A.5
Explanation: A contest will consist of n questions, each of which is to be answered eithertrueorfalse. anyone who answers all n questions correctly will be a winner. what is the least value of n for which the probability is less than 1/500 that a person who randomly guesses the answer to each question will be a winner?
A.5
B.10
C.50
D.100
E.1000
Soln: ans is B
Probability that one question is answered right is 1/2.
Now for minimum number of questions needed to take probability less than 1/1000 is
=> (1/2)^n < 1/1000
n = 10 satisfies this.
A
Question: The faces of a triangular prism are to be painted by 5 different colors. In how many ways can be this be done?
A.A.720
B.B.256
C.C.1
D.D.120
Answer: D.D.120
Explanation: If I have to paint 5 sides with 5 different colour...
First face can have 5c1 options,
2nd would have 4c1, and subsequent ones would have 3c1, 2c1 and 1 options respectively.
Total options = 5c1 x 4c1 x 3c1 x 2c1 x 1 = 120 distinct ways
Correct answer - D
Question: If 9a = 16b what is (4a + 6b)/(15a - 16b)
A.3
B.4
C.5
D.59/48
Answer: D.59/48
Explanation: 4a + 6b )/( 15a - 16b )
= (4a + 6b)/(15a - 9a) (because 9a = 16b)
= (4a + 6b)/6a
= 2/3 + b/a
= 2/3 + 9/16 (because 9a = 16b, so b/a = 9/16)
= (32+27)/48
= 59/48
ANSWER:D
Question: Conversation between two mathematicians:
First: I have three children. The product of their ages is 36. If you sum their ages, it is exactly same as my neighbor's door number on my left. The second mathematician verifies the door number and says that it is not sufficient. Then the first says "Ok one more clue is that my youngest is really the youngest". Immediately the second mathematician answers. Can you answer the question asked by the first mathematician? What are the children ages?
A.6,6, 1
B.6,6, 2
C.6,5, 1
D.6,5, 2
Answer: A.6,6, 1
Explanation: Possible options for same sum of ages ( 13 here)with product of ages as 36 are
2,2,9
and
6,6,1
but in case of 2,2,9
youngest is not really youngest as two children of age 2 years are twins.
whereas
in case of 6,6,1
youngest is really youngest.
so 6,6, 1 is correct.
ANSWER:A
Question: In the first half of the 20th century, the population of a particular country increased by 200 percent. In the second half of the century , the population increased by 300 percent. What was the percent increase for the 20th century as a whole?
A. 500%
B. 600%
C. 800%
D. 1100%
Answer: D. 1100%
Explanation: Say initially population was 100.
What is 200% of 100? It is 200 /100 * 100 = 200.
An increase of 200% means the new population became 100 + 200 = 300
What is 300% of 300? It is 300/100 * 300 = 900
An increase of 300% means the new population now is 300 + 900 = 1200
So from 100, the population increased to 1200 i.e. an increase of 1100.
1100 is what percent of 100?
1100 = x/100 * 100
i.e. it is 1100% D
Question: A wheel that has 6 cogs is meshed with a larger wheel of 14 cogs. If the smaller wheel has made 49 revolutions, what will be the number of revolutions made by the larger wheel?
A.15
B.12
C.21
D.9
Answer: C.21
Explanation: Explanation:
Let the number of revolutions made by the larger wheel be x
More cogs, less revolutions (Indirect proportion)
Hence we can write as
(cogs) 6 : 14 :: x : 49
â‡’6Ã—49=14 Ã— x
â‡’x = 21
Answer: Option C
Question: Mr. Thomas investe d an amount of Rs. 13,900 divided in two different schemes A and B at the simple interest rate of 14% p.a. and 11% p.a. respectively. If the total amount of simple interest earned in 2 years be Rs. 3508, what was the amount invested in scheme B?
A.Rs.6400
B.2878
C.2899
D.2660
Answer: A.Rs.6400
Explanation: Let the sum invested in scheme A be Rs. x and that in scheme B be Rs. (13900 - x). Then,
(x * 14 * 2)/100 + [(13900 - x) * 11 * 2]/100 = 3508
28x - 22x = 350800 - (13900 = 22)
6x = 45000 => x = 7500
So, sum invested in scheme B = (13900 - 7500) = Rs. 6400.Answer:A