RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: In a certain region, the number of children who have been vaccinated against rubella is twice the number who have been vaccinated against mumps. The number who have been vaccinated against both is twice the number who have been vaccinated only against mumps. If 4,000 have been vaccinated against both, how many have been vaccinated only against rubella?
A.2,5000
B.8,000
C.10,000
D.15,000
Answer: B.8,000
Explanation: Use a single variable as far as possible.
Number vaccinated only against mumps = x
Number vaccinated against both = 2x = 4000 (so x = 2000)
Then, number vaccinated against mumps (including both) = x + 2x = 3x
Number vaccinated against rubella = 2*3x = 6x
Then, number vaccinated against only rubella = 6x - 2x = 4x = 4*2000 = 8,000
Answer (B)
Question: Each of the dogs in a certain kennel is a single color. Each of the dogs in the kennel either has long fur or does not. Of the 45 dogs in the kennel, 26 have long fur, 22 are brown, and 8 are neither long-furred nor brown. How many long-furred dogs are brown?
A.26
B.19
C.11
D.8
Answer: C.11
Explanation: No of dogs=45
Long fur=26
Brown=22
Neither long fur nor brown=8
Therefore, either long fur or brown=45-8=37
37=26+22-Both
Both=11
Answer C
Question: A man can row 5 kmph in still water. If the river is running at 1kmph, it takes him 75 minutes to row to a place and back. How far is the place?
A.3km
B.2.5 km
C.4 km
D.5 km
Answer: A.3km
Explanation: Speed downstream = (5+1)km/hr = 6 km/hr Speed upstream = (5-1)km/hr = 4 km/hr Let the required distance be x km x/6 + x/4 = 75/60 2x+3x = 15 x = 3km .
ANSWER:A
Question: At a recent small town election for mayor a total of 983 votes were cast for the four candidates, the winner exceeding his opponents by 53, 79 and 105 votes, respectively. How many votes were cast for the candidate in fourth place?
A.134
B.178
C.200
D.166
Answer: C.200
Explanation: The number of votes the winning candidate received was
983 + 53 + 79 + 105	/4= 305.
The second received 305 – 53 = 252,
The fourth place received 305 – 105 = 200.
C
Question: A group of 10 representatives is to be selected out of 12 seniors and 10 juniors. In how many different ways can the group be selected if it should have at least one senior?
A.Â²Â²Câ‚â‚€
B.Â²Â²Câ‚â‚€+1
C.Â²Â²Câ‚‰ + Â¹â°Câ‚
D.Â²Â²Câ‚â‚€ - 1
Answer: D.Â²Â²Câ‚â‚€ - 1
Explanation: Explanation:
The total number of ways of forming the group of ten representatives is Â²Â²Câ‚â‚€.
The total number of ways of forming the group that consists of no seniors is Â¹â°Câ‚â‚€ = 1 way
The required number of ways = Â²Â²Câ‚â‚€ - 1
ANSWER IS D
Question: If x is an odd integer and y = 3x + 2, which of the following CANNOT be a divisor of y?
A.23
B.5
C.14
D.17
Answer: C.14
Explanation: x takes odd values as 1,3,5,7.,
y=3x+2
x is an odd term so 3x must be an odd term when it adds with 2 so it must be a odd integer
14 didn't follows this condition ans is C
Question: Fernando Alonso and Sebastian Vettel go for a car race. Bedore start of race, both of them have the exactly same amount of fuel in their respective cars. With the given fuel Fernando can drive continuously for 4 hours while Vettel can drive 1 hour more i.e five hours.
After a time they realize that amount of fuel left in Sebastian car is 4 times the fuel in Fernando car.
For long they are racing ?
A.15/4 hours
B.15/3 hours
C.15/2 hours
D.15/2 hours
Answer: A.15/4 hours
Explanation: Solution:
15/4 hours
Explanation:
Let us say they drive for "t" hours and initial fuel is "f"
Amount of fuel consumed by Fernando car is ft/4
Amount of fuel consumed by Sebastian car is ft/5
As per given condition,
f - ft/5 = 4(f-ft/4)
t = 15/4 hours
Answer A
Question: If the length of an edge of cube P is thrice the length of an edge of cube Q, what is the ratio of the volume of cube Q to the volume of cube P?
A.1/4
B.1/5
C.1/6
D.1/27
Answer: D.1/27
Explanation: The length of cube Q = 1;
The length of cube P = 3;
The ratio of the volume of cube Q to the volume of cube P = 1^3/3^3 = 1/27
Answer : D
Question: The parameter of a square is equal to the perimeter of a rectangle of length 36 cm and breadth 20 cm. Find the circumference of a semicircle whose diameter is equal to the side of the square. (Round off your answer to two decimal places)?
A.23.56
B.23.59
C.44.0
D.23.53
Answer: C.44.0
Explanation: Let the side of the square be a cm.
Parameter of the rectangle = 2(36 + 20) = 112 cm Parameter of the square = 112 cm
i.e. 4a = 112
A = 28
Diameter of the semicircle = 28 cm
Circimference of the semicircle
= 1/2(âˆ)(28)
= 1/2(22/7)(28) = 44cm to two decimal places
Answer:C
Question: If an item that originally sold for c dollars was marked up by a percent and then discounted by b percent, which of the following expressions represents the final price of the item?
A.(10,000c + 100c(a – b) – abc)/10,000
B.(10,000c + 100c(b – a) – abc)/10,000
C.(100c(a – b) – abc)/10000
D.(100c(b – a) – abc)/10000
Answer: A.(10,000c + 100c(a – b) – abc)/10,000
Explanation: Assume c=100, a=10, b=10. So final price is 99. Now put these value each option. Only option A will give right answer.
Question: A train 110 meters long takes 6 seconds to cross a man walking at 5 kmph in the direction opposite to that of the train. Find the speed of the train.
A.45 kmph
B.50 kmph
C.55 kmph
D.61 kmph
Answer: D.61 kmph
Explanation: Explanation:
Let the speed of the train be x kmph.
Speed of the train relative to man = (x + 5) kmph = (x + 5) ×5/18 m/sec.
Therefore 110/((x+5)×5/18)=6 <=> 30 (x + 5) = 1980 <=> x = 61
Speed of the train is 61 kmph.
Answer: Option D
Question: A bag contains 6 red and 3 green balls. Another bag contains 4 red and 6 green balls. If one ball is drawn from each bag. Find the probability that one ball is red and one is green.
A.19/20
B.17/20
C.7/15
D.8/10
Answer: C.7/15
Explanation: Let A be the event that ball selected from the first bag is red and ball selected from second bag is green.
Let B be the event that ball selected from the first bag is green and ball selected from second bag is red.
P(A) = (2/3) x (3/5) = 2/5.
P(B) = (1/3) x (2/5) = 2/15.
Hence, the required probability is P(A) + P(B) which is nothing but 7/15.
ANSWER:C
Question: If the average of 1, 2, 4, 5, 6, 9, 9, 10, 12 and x is 7, what is the value of x?
A.7
B.9
C.11
D.12
Answer: D.12
Explanation: Sum of the deviations of the numbers in the set from the mean is always zero
1, 2, 4, 5, 6, 9, 9, 10, 12
mean is 7
so the list is -6-5-3-2-1+2+2+3+5... this shud total to zero
but this is -5 , hence we need a number that is 5 more than the mean to get a +5 and make it zero
hence the answer is 7 + 5 = 12
D
Question: A boat takes 38 hours for travelling downstream from point A to point B and coming back to point C midway between A and B. If the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph, what is the distance between A and B?
A.240 km
B.120 km
C.360 km
D.180 km
Answer: C.360 km
Explanation: Explanation :
velocity of the stream = 4 kmph
Speed of the boat in still water is 14 kmph
Speed downstream = (14+4) = 18 kmph
Speed upstream = (14-4) = 10 kmph
Let the distance between A and B be x km
Time taken to travel downstream from A to B + Time taken to travel upstream from B to C(mid of A and B) = 38 hours
⇒x/18+(x/2)10=38
⇒x/18+x/20=38
⇒19x/180=38
⇒x/180=2
⇒ x = 360
i.e., the distance between A and B = 360 km. Answer : Option C
Question: The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
A.7
B.4
C.12
D.19
Answer: D.19
Explanation: Average of 20 numbers = 0
Sum of 20 numbers = (0 * 20) = 0
It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (-a).
Answer: D
Question: a' and 'b' are positive integers such that their LCM is 20 and their HCF is 1. What is the difference between the maximum and minimum possible values of 'a - b'?
A.28
B.29
C.34
D.38
Answer: D.38
Explanation: possible values of a and b can be 5,4; 4,5 and 1,20; 20,1
maximum possible value for a-b is 20-1=19
minimum possible value for a-b is 1-20=-19
19-(-19)=38 ans is D
Question: Three candidates contested in an election and received 1136, 7636, 11628 votes respectively. What is the percentage of the total votes did the winning candidate get?
A.45%
B.49%
C.57%
D.51%
Answer: C.57%
Explanation: Total number of votes polled = 1136+7636+11628 = 20400
Required percentage = 11628*100/20400 = 57%
Answer is C
Question: If 50% of (x-y) = 20% of (x+y), then what percent of x is y?
A.50.5%
B.42.8%
C.22.2%
D.33.3%
Answer: B.42.8%
Explanation: 50% of (x-y) = 20% of (x+y)
50/100 (x-y) = 20/100 (x+y)
3x = 7y
Required percentage = y/x *100 = 3y/7y * 100 = 42.85%
Answer is B
Question: In how many years, Rs. 300 will produce the same interest at 6% as Rs. 800 produce in 2 years at 4½% ?
A.4 years
B.6 years
C.8 years
D.9 years
Answer: A.4 years
Explanation: Explanation :
Let Simple Interest for Rs.300 at 6% for n years = Simple Interest for Rs.800 at 4½ % for 2 years
300×6×n/100=800×9/2×2/100
300×6×n=800×9/2×2
300×6×n=800×9
n=4 years
Answer : Option A
Question: What is the units digit of 32! + 50! + 2! + 4!?
A.0
B.2
C.4
D.6
Answer: D.6
Explanation: For all N greater than 4, the units digit of N! is 0.
The sum of the four units digits is 0 + 0 + 2 + 4 = 6
The units digit is 6.
The answer is D.
Question: Sharmila works 10 hours per day on Monday, Wednesday and Friday, and 8 hours per day on Tuesday and Thursday. She does not work on Saturday and Sunday. She earns $460 per week. How much does she earn in dollars per hour?
A.8
B.9
C.9.5
D.10
Answer: D.10
Explanation: So, she works 30 hours in 3 days
So, she works 16 hours in 2 days
So in a week she works 46 hours ( 30 + 16 ) and earns $460
So, Hourly wage is 460/46 => 10
Hence answer will be (D) 10
Question: If (4 - x)/(5 + x) = x, what is the value of x^2 + 6x - 4?
A.-3
B.0
C.2
D.4
Answer: B.0
Explanation: (4-x) = x*(5+x)
(4-x) = 5x+x^2
0 = x^2+6x-4
The answer is B.
Question: A whale goes on a feeding frenzy that lasts for 12 hours. For the first hour he catches and eats 30 kilos of plankton. In every hour after the first, it consumes 2 kilos of plankton more than it consumed in the previous hour. If by the end of the frenzy the whale will have consumed a whopping accumulated total 600 kilos of plankton, how many kilos did he consume on the 10th hour?
A.36
B.45
C.28
D.48
Answer: D.48
Explanation: Therefor in 10th hour he consume x+2*9=30+18=48
correct option is D
Question: From a class consisting of 12 computer science majors, 10 mathematics majors, and 9 statistics majors, a committee of 4 computer science majors, 4 mathematics majors, and 3 statistics majors is to be formed. How many distinct committees are there?
A.15200
B.16200
C.17200
D.18000
Answer: B.16200
Explanation: From a class consisting of 12 computer science majors, 10 mathematics majors, and 9 statistics majors, a committee of 4 computer science majors, 4 mathematics majors, and 3 statistics majors is to be formed. How many distinct committees are there?
Alright, I just started learning combinations tonight, but I have hit a wall. I ran across this problem but cannot get the answer right. Apparently, the answer is 8-some-thousand, but I keep coming up with 16,200. This is how I am working it.
12!/4!(12-4)! * 10!/4!(10-4)! * 9!/3!(9-3!)
(12*...*1/4*...*1*8*...1) * (10*...*1/4*...1*6...*1) * (9*...1/3*2*1*6*...1)
(12*10*9/4*3*2*1) * (10*9*8*7/4*3*2*1) * (9*8*7/3*2*1)
(3*5*3/1*1*1) * (5*3*7/1*1*1) * (3*4*7/1*1*1)
45 * 30 * 12
Answer: 16,200 B
Question: A certain car's price decreased by 2.5% (from the original price) each year from 1996 to 2002, during that time the owner of the car invested in a new carburetor and a new audio system for the car, which increased car's price by $1,000. If the price of the car in 1996 was $22,000, what is the car's price in 2002?
A.$18,400
B.$19,700
C.$20,200
D.$20,400
Answer: B.$19,700
Explanation: Price in 96 = 22000
Price decrease each year = 2.5/100*22000 = 550
Price in 97 = 22000 - 550
Price in 98 = 22000 - 2*550
Price in 99 = 22000 - 3*550
Price in 00 = 22000 - 4*550
Price in 01 = 22000 - 5*550
Price in 02 = 22000 - 6*550 = 18700
Investment in the car = 1000
Net price of the car in 02 = 18700 + 1000 = $19700
Correct Option: B
Question: What is the area M of the square with the following coordinates: (x, y), (20, 20), (20, 5), (x, 5)?
A.60.
B.85.
C.125.
D.225.
Answer: D.225.
Explanation: Length of one side= 15 (20-5)
Since, its a square, the area will be M= 15^2= 225
D is the answer
Question: The speed of a car is 120 km in the first hour and 70 km in the second hour. What is the average speed of the car?
A.72 kmph
B.75 kmph
C.95 kmph
D.80 kmph
Answer: C.95 kmph
Explanation: S = (120 + 70)/2
= 95 kmph
ANSWER:C
Question: An air conditioner can coo the hall in 12 minutes while another takes 15 minutes to cool under similar conditions. if both air conditioners are switched on at same instance then how long will it take to cool the room?
A.about 7 minutes
B.about 8 minutes
C.about 9 minutes
D.about 10 minutes
Answer: A.about 7 minutes
Explanation: Take LCM of 12 and 15 = 60
12*5=60/ 15*4=60.
So if both are switched on together , room cooled in 60/(5+4)=60/9=6.66 minutes
6.66 can be round to 7 minutes , so about 7 minutes
ANSWER: A
Question: The cost price of 13 articles is equal to the selling price of 11 articles. Find the profit percent?
A.18 2/71%
B.18 2/11%
C.18 2/15%
D.18 2/19%
Answer: B.18 2/11%
Explanation: 13 CP = 11 SP
11 --- 2 CP
100 --- ? =>18 2/11%
Answer: B
Question: 4000 was divided into two parts such a way that when first part was invested at 3% and the second at 5%, the whole annual interest from both the investments is Rs.144, how much was put at 3%?
A.2800
B.2500
C.3000
D.3500
Answer: A.2800
Explanation: (x*3*1)/100 + [(4000 - x)*5*1]/100 = 144
3x/100 + 200 â€“ 5x/100 = 144
2x/100 = 56 Ã¨ x = 2800
ANSWER A
Question: John deposited $10,000 to open a new savings account that earned 6 percent annual interest, compounded quarterly. If there were no other transactions in the account, what was the amount of money in John’s account 6 months after the account was opened?
A.$10,100.30
B.$10,101.50
C.$10,200.75
D.$10,302.25
Answer: D.$10,302.25
Explanation: 6 percent annual interest compounded quarterly --> 1.5% in 3 moths.
For the first 3 moths interest was 1.5% of $10,000, so $150;
For the next 3 moths interest was 1.5% of $10,000,plus2.25 earned on previous interest of $150, so $150+$2.25=$152.25;
Total interest for 6 months was $150+$152.25=$302.25, hence balance after 6 months was $10,000+ $302.25=$10,302.25.
Answer: D.
Question: 90kg of an alloy A is mixed with 140 kg of alloy B. If alloy A has lead and tin in the ratio 3:4 and alloy B has tin and copper in the ratio 2:5, then the amount of tin in the new alloy is?
A.100.6kg
B.95.4kg
C.117.5kg
D.91.4kg
Answer: D.91.4kg
Explanation: Quantity of tin in 90kg of A = 90*4/7 = 51.4kg
Quantity of tin in 140kg of B = 140*2/7 = 40kg
Quantity of tin in the new alloy = 51.4+40 = 91.4kg
Answer is D
Question: The Natural Woman, a women's health food store, offers its own blends of trail mix. If the store uses 4 different ingredients, how many bins will it need to hold every possible blend, assuming that each blend must have at least three ingredients? (Also assume that each bin can hold one and only one blend.)
A. 1
B. 4
C. 5
D. 11
Answer: C. 5
Explanation: We're told that there are 4 ingredients (we'll call them A, B, C and D); we're told that each 'mix' must include AT LEAST 3 ingredients...
3 ingredient blends:
ABC
ABD
ACD
BCD
4 ingredient blends:
ABCD
Total blends =4+1 = 5
C
Question: If two numbers, a and b, are to be chosen from a set of 4 consecutive integers starting with 1 and a set of four consecutive even integers starting with 10, respectively, what is the probability that b/a will not be an integer?
A.3/16
B.1/4
C.5/16
D.3/8
Answer: C.5/16
Explanation: a is from the following set {1,2,3,4}
b is from the following set {10,12,14,16}
The total number of ways of choosing 2 integers, one from each set is 4*4 = 16 ways.
The possibilities where b/a is not an integer is for the following outcomes:
{b,a} = {10,3},{10,4},{14,3},{14,4},{16,3} = 5 ways
Thus the probability is 5/16
The answer is C.
Question: Lastly, jenny compared Canada’s CN Tower and Seattle’s Space
Needle. How tall is the Space Needle if the CN Tower stands at 553m
high and it is taller than the Space Needle by 369m?
A.127
B.184
C.170
D.113
Answer: B.184
Explanation: 553-369=184.Answer is B.
Question: A student chose a number, multiplied it by 6, then subtracted 250 from the result and got 122. What was the number he chose?
A.59
B.60
C.61
D.62
Answer: D.62
Explanation: Let x be the number he chose, then
6⋅x−250=122
6x=372
x=62
correct answer D
Question: Min (a, b, c)=min of a, b, c Max (a, b, c,)=max of a, b, c then what is the value of MAX {min (2,5,7), max (-7, -2, -3), 3}
A.1
B.2
C.3
D.4
Answer: C.3
Explanation: MAX {min (2,5,7), max (-7, -2, -3), 3}
= MAX {2,-2,3}
=3
ANSWER:C
Question: A teacher of 6 students takes 2 of his students at a time to a zoo as often as he can, without taking the same pair of children together more than once. How many times does the teacher go to the zoo?
A.12
B.15
C.10
D.48
Answer: B.15
Explanation: Two students can be selected from 6 in 6C2 =15 ways.
Therefore, the teacher goes to the zoo 15 times.
Ans: B
Question: If x and y are positive integers such that x/y = 2.60, which of the following numbers could be y?
A.3
B.4
C.6
D.5
Answer: D.5
Explanation: With the given information, we are trying to find the value of y.
To achieve this we must convert the given decimal to a fraction and reduce it to it's lowest integer form.
Take the decimal x/y = 2.60 and because it's in the hundreds decimal place, put the given value (x/y = 2.60/1) and multiply it by 100.
Take the resulting fraction (x/y = 260/100) and reduce it to it's lowest form.
Both of the numbers are divisible by 20.
The result is x/y = 13/5.
Thus y = 5.
The correct answer is D.
Question: Initially two cups of same volume are present with milk filled upto 3/5th and 4/5th of their volumes.Water is then filled. Then two mixtures are mixed. Find the ratio of water to milk in the mixture
A.1/7
B.2/7
C.3/7
D.4/7
Answer: C.3/7
Explanation: water content can b in 1st and second is 2/5 and1/5 total:3/5.the total milk content is 7/5.the ratio is ((3/5)/(7/5))=3/7.
ANSWER:C
Question: What smallest number should be added to 8444 such that the sum is completely divisible by 7 ?
A.6
B.5
C.4
D.3
Answer: B.5
Explanation: Explanation:
8444 ÷ 7 = 1206, remainder = 2
7 - 2 = 5
Hence, 5 should be added to 8444 such that the sum is completely divisible by 7.
Answer: B
Question: The average age of a family of 5 members is 20 years. If the age of the youngest member be 10 years then what was the average age of the family at the time of the birth of the youngest member?
A.13.5
B.14
C.15
D.12.5
Answer: D.12.5
Explanation: Solution:
At present the total age of the family = 5*20 =100.
The total age of the family at the time of the birth of the youngest member,
=[100−10−(10*4)]=50.
Therefore, average age of the family at the time of birth of the youngest member,
= 50/4 = 12.5.
Answer: Option D
Question: Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 27 seconds. What is the length of each train (in meters)?
A.50.5
B.88.5
C.37.5
D.55.5
Answer: C.37.5
Explanation: The relative speed = 46 - 36 = 10 km/hr = 10 * 5/18 = 25/9 m/s
In 27 seconds, the relative difference in distance traveled is 27 * 25/9 = 75 meters
This distance is twice the length of each train.
The length of each train is 75/2 = 37.5 meters
The answer is C.
Question: 180 metres long yard, 11 trees are palnted at equal distances, one tree being at each end of the yard. What is the distance between 2consecutive trees
A.18
B.12
C.14
D.16
Answer: A.18
Explanation: 11 trees have 10 gaps between them,
Required distance (180/10) = 18
A
Question: If x and y are integers such that x^2+4x+2y+6=2x^2+5x+y-6, we can deduce that y is
A.not an even
B.an even
C.a perfect square
D.an odd
Answer: B.an even
Explanation: x^2 + 4x + 2y + 6 = 2x^2 + 5x + y - 6
y = x^2 + x - 12
y = (x+4)(x-3) (Note that one factor is even and one factor is odd.)
Then y must be even.
The answer is B.
Question: A, B and C can do a work in 7 , 14 and 21 days respectively. They completed the work and got Rs.242. What is the share of C?
A.33
B.44
C.55
D.77
Answer: B.44
Explanation: The ratio of their working rates = 1/7 : 1/14 : 1/21 = 6 : 3 : 2.
Since, they work together, the share of C
= 2/11 * 242 = Rs.44
\Answer: B
Question: Three boys are ages 4, 6 and 7 respectively. Three girls are ages 5, 8 and 9, respectively. If two of the boys and two of the girls are randomly selected and the sum of the selected children's ages is q, what is the difference between the probability that q is even and the probability that q is odd?
A. 1/9
B. 1/6
C. 2/9
D. 1/4
Answer: A. 1/9
Explanation: Age of Boys q:4, 6, 7
Sum of ages taken 2 at a time: 10,13,11
Ages of Girls:5, 8, 9
Sum of ages taken 2 at a time: 13,17,14
9 Combinations of sum between sets(10,12,11)(13,17,14)
=23,27,24- 16,30,17- 24,28,25
Prob(Even)= 5/9
Prob(Odd) =4/9
Answer=5/9 - 4/9 = 1/9
Question: On average, activated yeast cells divide once every 120 minutes; that is, each individual cell divides into two individual cells over that time span. Given that a certain yeast colony consisted of 180,000 cells two hours ago, approximately how many cells will be populating the colony six hours from now?
A.77,500
B.1,860,000
C.2,880,000
D.3,720,000
Answer: C.2,880,000
Explanation: 180,000 × 2 × 2×2×2 = 180,000 × 16 = C
Question: Having received his weekly allowance, a student spent 3/5 of his allowance at the arcade. The next day he spent one third of his remaining allowance at the toy store, and then spent his last $0.60 at the candy store. What is this student’s weekly allowance?
A.$2.25
B.$2.75
C.$3.00
D.$3.50
Answer: A.$2.25
Explanation: Let x be the value of the weekly allowance.
(2/3)(2/5)x = 60 cents
(4/15)x = 60
x = $2.25
The answer is A.
Question: Four bells commence tolling together and toll at intervals of 2, 3, 4 and 5 seconds respectively. In 10 minutes, how many times do they toll together ?
A.10
B.11
C.12
D.13
Answer: B.11
Explanation: LCM of 2, 3, 4, and 5 is 60.
So, after each 60 seconds, they would toll together.
Hence, in 10 minutes, they would toll 10*60 seconds / 60 seconds = 10 times
But then the question says they commence tolling together. So, they basically also toll at thebeginning(0second).
So, total tolls together = 10+1 = 11
Answer: B
Question: The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 120 metres?
A.22 seconds
B.65 seconds
C.24 seconds
D.12 seconds
Answer: C.24 seconds
Explanation: Speed of the boat downstream
= 15 + 3 = 18 kmph
= 18 * 5/18 = 5 m/s
Hence time taken to cover 60 m
= 120/5 = 24 seconds.
Answer:C
Question: A straight pipe 6 yard in length was marked off in fourths and also in thirds. If the pipe was then cut into separate pieces at each of these markings, which of the following gives all the different lengths of the pieces, in fractions of a yard?
A. 1/6 and 1/4 only
B. 1/4 and 1/3 only
C. 1/6, 1/4, and 1/3
D. 1/12, 1/6 and 1/4
Answer: B. 1/4 and 1/3 only
Explanation: Since we want to find the fractions, we can assume some other length of the pipe which will make calculation easier. Take the length of the pipe to be 12-meter long (the least common multiple of 3 and 4.
In this case the branch would be cut at3,4, 6,8, and 9meters (in black are given fourths of the length and in red thirds of the length).
Distinct lengths would be: 3=3/12=1/4, 4-3=1=1/3 meters long pieces.
Answer: B.
Question: The average height of 20 students is 20 cm and the average height of 11 students is 20 cm . What is the average height of the 31 students?
A.40 cm
B.20 cm
C.30 cm
D.25 cm
Answer: B.20 cm
Explanation: The total height of the 31 students =(20 * 20) + (11 * 20) = 400 + 220 = 620 cm The required average height =620/31 = 20 cm Answer :B