RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: If R is a positive integer, and R/15 = 8.2, what is the remainder when R is divided by 15?
A.A.1
B.B.2
C.C.3
D.D.4
Answer: C.C.3
Explanation: If R were a multiple of 15, the quotient R/15 would be an integer. The fact that it's a decimal tells us that 15 goes into R eight whole times and some decimal part of a time. This decimal part, 0.2 is the remainder divided by the divisor. Let B be the remainder.
B/15 = 0.2 = 1/5
B = (15)*(1/5) = 3
Answer =(C)
Question: In shop contains 500 articles each of a cost of $10. He sold them at a price of $11. If the shop keeper has a order of 200 articles, how much profit he will get?
A.A)2100
B.B)2000
C.C)1500
D.D)200
Answer: D.D)200
Explanation: Total money after selling articles = 200*11 = 2200
cost price = 200*10 = 2000
profit = 200
correct option is D
Question: A man has some hens and cows. If the number of heads be 48 and the number of feet equals 144, then the number of hens will be:
A.22
B.23
C.24
D.26
Answer: C.24
Explanation: let hens be x and cows be y
now,
feet: x*2+y*4=144
heads: x*1+y*1=48
implies, 2x+4y=144 and x+y=48
solving these two equations, we get x=24 and y=24
Therefore, hens are 26.
ANSWER:C
Question: There r 4 prime numbers in ascending order. The multiplication of first 3 is 385 and that of last 3is 1001. what is the last number is
A.10
B.12
C.11
D.13
Answer: D.13
Explanation: Explanation:
abcbcd=3851001=>ad=513
abcbcd=3851001=>ad=513
So d = 13
D
Question: Which of the numbers below is the odd one out
1,3,7,13,24,21,31.
A.3
B.7
C.21
D.24
Answer: D.24
Explanation: 24 is the odd man.. diff between sucessive no.s are multiples of 2
ANSWER:D
Question: Amar takes as much time in running 18 meters as a car takes in covering 48 meters. What will be the distance covered by Amar during the time the car covers 1.6 km?
A.277
B.289
C.269
D.600
Answer: D.600
Explanation: Distance covered by Amar = 18/4.8 (1.6km)
= 3/8(1600)
= 600 m
Answer: D
Question: What will be 60 percent of a number whose 200 percent is 90 ?
A.144
B.72
C.27
D.None of these
Answer: C.27
Explanation: Answer
∵ 200% of N = 90
⇒ N = (90 x 100) / 200 = 45
∴ 60% of N = (60 x 45) / 100 = 27
Correct Option: C
Question: Find the smallest number in a GP whose sum is 38 and product 1728
A.12
B.20
C.8
D.All of these
Answer: C.8
Explanation: In GP :- a/r+a+ar....=38
a(1+r+r^2)=38r......eq1
Product a^3=1728
a=12
now put this value in eq1
12(1+r+r^2)=38r
r=2/3 and 3/2..so sallest number is 8
ANSWER:C
Question: A jar full of whisky contains 30% alcohol. A part of this whisky is replaced by another containg 19% alcohol and now the percentage of alcohol was found to be 26%. What quantity of whisky is replaced ?
A.1/3
B.2/3
C.2/5
D.3/5
Answer: A.1/3
Explanation: Let us assume the total original amount of whiskey = 10 ml ---> 4 ml alcohol and 6 ml non-alcohol.
Let x ml be the amount removed ---> total alcohol left = 4-0.4x
New quantity of whiskey added = x ml out of which 0.19 is the alcohol.
Thus, the final quantity of alcohol = 4-0.4x+0.19x ----> (4-0.21x)/ 10 = 0.26 ---> x = 20/3 ml.
Per the question, you need to find the x ml removed as a ratio of the initial volume ---> (20/3)/10 = 1/3.
Hence, A is the correct answer.
Question: At a dinner party, 5 people are to be seated around a circular table. 2 seating arrangements are considered different only when the positions of the people are different relative to each other. what is the total number E of different possible seating arrangements for the group?
A.5
B.10
C.24
D.32
Answer: C.24
Explanation: Circular arrangements= (n-1)!
Hence (4!) = 24=E
Answer is C
Question: If a and b are both odd numbers, which of the following is an odd number?
A.a + b
B.a + b + 2
C.ab+2
D.ab + 1
Answer: C.ab+2
Explanation: Sol.
Product of two odd numbers is always odd and adding 2 gives odd.
Answer C
Question: If y is 70% greater than x, than x is what % less than y?
A.18.7
B.25.5
C.33.3
D.41.2
Answer: D.41.2
Explanation: y = 1.7x
x = y/1.7 = 10y/17
x is 7/17 less which is about 41.2% less than y.
The answer is D.
Question: 31 of the scientists that attended a certain workshop were Wolf Prize laureates, and 14 of these 31 were also Nobel Prize laureates. Of the scientists that attended that workshop and had not received the Wolf prize, the number of scientists that had received the Nobel Prize was 3 greater than the number of scientists that had not received the Nobel Prize. If 50 of the scientists attended that workshop, how many of them were Nobel Prize laureates?
A.A)11
B.B)18
C.C)25
D.D)29
Answer: C.C)25
Explanation: lets solve by creating equation..
W = 31..
Total = 50..
Not W = 50 -31= 19..
Now let people who were neither be x, so out of 19 who won Nobel = x+3..
so x+x+3=19 or x=8..
so who won Nobel but not Wolf = x+3 = 11..
But people who won BOTH W and N = 13..
so total who won N = 11+14 = 25..
C
Question: The difference between the simple interest received from two different sources on Rs. 1500 for 3 years is Rs. 13.50. The difference between their rates of interest is?
A.0.9%
B.0.4%
C.0.3%
D.0.2%
Answer: C.0.3%
Explanation: (1500 * R1 * 3)/100 - (1500 * R2 * 3)/100 = 13.50 4500(R1 - R2) = 1350
R1 - R2 = 0.3%
Answer: C
Question: A, B and C are partners. A receives 2/3 of profits, B and C dividing the remainder equally. A's income is increased by Rs.200 when the rate to profit rises from 5 to 7 percent. Find the Capital of B?
A.3999
B.7799
C.2500
D.2772
Answer: C.2500
Explanation: A:B:C = 2/3:1/6:1/6 = 4:1:1
x * 2/100 * 2/3 = 200
B capital = 15000*1/6 = 2500.Answer: C
Question: What is the sum of the multiples of 4 between 19 and 130 inclusive?
A.2012
B.2044
C.2060
D.2072
Answer: D.2072
Explanation: the fastest way in an AP is to find the average and multiply with total integers..
between 19 and 130, the smallest multiple of 4 is 20 and largest =128..
average=(20+128)/2=148/2=74.
total numbers = (128-20)/4 + 1= 27+1=28..
sum=28*74=2072
ans D
Question: The average of first five prime numbers greater than 3 is?
A.32.2
B.10.6
C.32.3
D.32.8
Answer: B.10.6
Explanation: 5 + 7 + 11 + 13 + 17
= 53/5
= 10.60
Answer = B
Question: Find compound interest on Rs. 7500 at 4% per annum for 2 years, compounded annually
A.Rs 312
B.Rs 412
C.Rs 512
D.Rs 612
Answer: D.Rs 612
Explanation: Explanation:
Please apply the formula
Amount=P(1+R100)nC.I. = Amount - P
Answer: D
Question: A can contains a mixture of liquids A and B is the ratio 7:5. When 9 litres of mixture are drawn off and the can is filled with B, the ratio of A and B becomes 7:9. How many liter E of liquid A was contained by the can initially?
A.10
B.20
C.21
D.25
Answer: C.21
Explanation: As A:B::7:5 ---> only option C is a multiple of 7 and hence it is a good place to start. Also A:B::7:5 means that , A = (712)*Total and B = (5/12)*Total
If A = 21 , B = 15 ---> remove 9 litres ---> you remove (7/12)*9 of A ---> A remaining = 21-(7/12)*9 = 63/4
Similarly, for B, you remove (5/12)*9 ---> B remaining = 15 - (5/12)*9 = 45/4 and then add 9 more litres of B ---> 9+45/4 = 81/4
Thus A/B (final ratio) = (45/4)/(81/4) = 7:9 , the same as the final ratio mentioned in the question.
Hence C is the correct answer.
A/B = 7/9 = (7x-(7/12)*9)/ (5x-(5/12)*9+9), where 7x and 5x are initial quantities of A and B respectively.
Thus, 7/9 = (7x-(7/12)*9)/ (5x-(5/12)*9+9) ---> giving you x=3. Thus A (original) E= 7*3 = 21.C
Question: Kate is 12 years old. His age is 4 times the age of Robbie. Find the age of Robbie.
A.1yrs
B.2yrs
C.3yrs
D.4yrs
Answer: C.3yrs
Explanation: Let Kate age, x = 12
robbie = x/4
=12/4
=3yrs
ANSWER:C
Question: Five years ago, the average age of A, B, C and D was 45 years. With E Joining them now, the average of all the five is 51 years. The age of E is?
A.45
B.47
C.55
D.49
Answer: C.55
Explanation: Solution
5 years ago average age of A,B,C,D = 45 years
=> 5 years ago total age of A, B, C, D = 45 x 4 = 180 years
=> Total present age of A, B, C, D = 180 + 5x4 = 200 years
If E's present age is x years = 200+x/5= 51
x=55 years. Answer C
Question: At a certain high school, a student’s popularity is determined by his or her locker number. Whoever has the locker number with the greatest number of distinct prime factors is the most popular student in the school. If Dhoni ,Kamal, Gokul, and Dinesh get lockers with the numbers 50, 400, 150, and 25, respectively, who is the most popular student?
A.Dhoni
B.Kamal
C.Gokul
D.Dinesh
Answer: C.Gokul
Explanation: Distinct prime factors of 50 (Dhoni) : 2,5
Distinct prime factors of 400 (Kamal): 2 and 5.
Distinct prime factors of 150 (Gokul): 2,3, and 5
Distinct prime factors of 25 (Dinesh): 5.
So most popular student - Gokul
Answer C
Question: If 4 and 11 are the lengths of two sides of a triangular region, which of the following can be the length of the third side?
I. 5
II. 13
III. 15
A.I only
B.II only
C.I and II only
D.II and III only
Answer: B.II only
Explanation: The length of any side of a triangle must be larger than the positive difference of the other two sides, but smaller than the sum of the other two sides.
i.e let us assume the third side be c and other sides be a and b, then as per rule
c > a - b and c < a + b.
Let's take options
option 1. the three sides will be 5 , 4 and 11..
then 11 > 5-4 --Yes
11 < 4+9...NO
option 2... 13, 4 and 11.
then 13 > 11-4...Yes
13 < 11+4...Yes
Option 3..15 ,4 and 11.
15 < 11+4...No
15 > 11-4...Yes...
Only 13 is correct .
Answer: option B is correct..
Question: Tim and Élan are 90 miles away from one another. They are starting to move towards each other simultaneously, Tim at a speed of 10 Mph and Élan at a speed of 5 Mph. If every hour they double their speeds, what is the distance that Tim will pass until he meets Élan?
A.30 miles.
B.35 miles.
C.45 miles.
D.60 miles.
Answer: D.60 miles.
Explanation: In 1st hour: Relative speed of the two will be 10+5 = 15 miles / hour. As they move towards each other, The distance between them reduces by 15 miles. Distance left between them: 90 - 15 = 75 miles.
In 2nd hour: Speed of Tim: 20Mph, That of Elan: 10 Mph. Relative speed of the two will be 20+ 10 = 30 miles / hour. As they move towards each other, The distance between them reduces by 30 miles. Distance left between them: 75 - 30 = 45 miles.
In 3rd hour: Speed of Tim: 40 Mph, That of Elan: 20 Mph. Relative speed of the two will be 40+ 20 = 60 miles / hour.
Now in order to cover the remaining distance of 45 miles. They will take: (45/ 60) hrs. = (3/4) hour.
Distance travelled by Tim?
In first hour: 1 hour * (10 miles per hour) = 10 miles
In second hour: 1 hour * (20 miles per hour) = 20 miles
In third hour: (3/4) hour * (40 miles per hour) = 30 miles
Total distance travelled: 10+20+30 = 60 miles.
D is the answer
Question: Peeta asks Katniss, 'It is 10 am as per my watch right now.Do you know what will be the time 23, 999, 999 hours later?'
Katniss knows the answer. Do you ?
A.5pm
B.6pm
C.4am
D.7am
Answer: D.7am
Explanation: D
7pm
The time after 24, 000, 000 hours will be the same as it is now. We want the time 3 hours before that and thus you can deduct three hours from 9 pm. So the time will be 6 pm.
Question: There was a cycle race going on. 1/5th of the those in front of a person and 5/6th of those behind him gives the total number of participants. How many people took part in the race?
A.30
B.31
C.32
D.33
Answer: B.31
Explanation: let total =x
1/5*(x-1)+5/6(x-1)=x by solving this we will get 31
ANSWER:B
Question: A retailer sold two articles at a profit percentage of 10% each. The cost price of one article is three – fourth that of the other. Find the ratio of the selling price of the dearer article to that of the cheaper one
A.4:3
B.3:4
C.41:31
D.51:41
Answer: A.4:3
Explanation: Let C.P of one of the article be X, Then C.P of the other = ¾X,
S.P 1 = 11X/10, S.P2 =3/4*11/10X,
S.P1/S.P2 = 11X/10 *40/33X = 4/3
S.P1: S.P2 = 4 : 3
ANSWER:A
Question: A tradesman by means of his false balance defrauds to the extent of 20%? in buying goods as well as by selling the goods. What percent does he gain on his outlay?
A.56%
B.44%
C.78%
D.55%
Answer: B.44%
Explanation: B
g% = 20 + 20 + (20*20)/100
= 44%
Question: A crow leaves its nest, and flies back and forth from its nest to a nearby ditch to gather worms. The distance between the nest and the ditch is 400 meters. In one and a half hours, the crow manages to bring worms to its nest 15 times. What is the speed of the crow in kilometers per hour?
A.2
B.4
C.6
D.8
Answer: D.8
Explanation: The distance between the nest and the ditch is 400 meters.
15 times mean = A crow leaves its nest, and flies back ( going and coming back) i.e. 2 times we get total 30 rounds.
So the distance is 30 * 400 = 12000.
D = ST
12000/1.5 = T , I think we can take 12000 meters as 12km, then only we get T = 8.( 1000 meters = 1 km)
D)
Question: If the least common multiple of two prime numbers x and y is 10, where x > y, then the value of 2x + y is
A.7
B.9
C.11
D.12
Answer: D.12
Explanation: LCM of two prime numbers will basically be multiple of those numbers. LCM = 10 = 2*5, both of which are prime.
Now we know x>y, so x=5 and y =2.
2x+y = 2*5 + 2 = 10 + 2 = 12.
ANSWER:D
Question: In a board game, a stack of 46 cards, 8 of which have pictures of fruit, are shuffled and then placed face down. If the first 2 cards selected do not have pictures of fruit, what is the probability that the third card selected will have a picture of fruit?
A.2/11
B.1/6
C.1/8
D.3/7
Answer: A.2/11
Explanation: After 2 cards have been selected, there are 44 cards remaining.
P(third card has a picture of fruit) = 8/44 = 2/11
The answer is A.
Question: Jacob is now 13 years younger than Michael. If 9 years from now Michael will be twice as old as Jacob, how old will Jacob be in 4 years?
A. 8
B. 7
C. 15
D. 21
Answer: A. 8
Explanation: Jacob=x years, Michael=x+13 years
9 years from now,
2(x+9)=x+22
2x+18=x+22
x=4
x+4=8 years
Answer A
Question: Lakshmi invested some money in 25% stock at 500.If Usha wants to invest in an equally good 50% stock ,he must purchase a stock worth of :
A.Rs. 1000
B.Rs. 1200
C.Rs. 1300
D.Rs. 1400
Answer: A.Rs. 1000
Explanation: Solution
For an income of Rs. 25, investment = Rs. 500
For an income of Rs. 50, investment = Rs.(500/25x50) = Rs. 1000
Answer A
Question: The size of a flat-screen television is given as the length of the screen’s diagonal. How many square inches greater is the screen of a square 24-inch flat-screen television than a square 17-inch flat-screen television?
A.143.5
B.154
C.160
D.148.75
Answer: A.143.5
Explanation: If we take a square with side length x and draw a diagonal, we get two isosceles right triangles.
If we focus on one such right triangle, we see that the legs have length x.
square 24-inch flat-screen television
The diagonal (hypotenuse) = 24
So, we can apply the Pythagorean Theorem to get x² + x² = 24²
Simplify: 2x² = 24²
Divide both sides by 2 to get: x² = 24²/2
Since the area of the square = x², we can see that the area of this square is 24²/2
square 17-inch flat-screen television
The diagonal (hypotenuse) = 17
So, we can apply the Pythagorean Theorem to get x² + x² = 17²
Simplify: 2x² = 17²
Divide both sides by 2 to get: x² = 17²/2
Since the area of the square = x², we can see that the area of this square is 17²/2
DIFFERENCE IN AREAS =24²/2-17²/2
= 288 -144.5 i.e = 143.5
A
Question: A man said to his son, "I was two-third of your present age when you were born". If the present age of the man is 48 years, find the present age of the son?
A.25.7 years
B.28 years
C.29.3 years
D.28.8 years
Answer: D.28.8 years
Explanation: Present age of the son be P, he was born P years ago.
The age of the man was: (48 - P).
His age when the son was born should be equal to 2/3 of P.
(48 - P) = 2/3 P
5P = 144 => P = 28.8
ANSWER:D
Question: what is the sum of the first 25 odd natural numbers
A.300
B.400
C.625
D.600
Answer: C.625
Explanation: sum of first n odd natural nuber is = n^2
so sum of the first 25 odd natural numbers=(25)^2=625
ans 625
ANSWER:C
Question: Find the smallest number which when divided by 13 and 16 leaves respective remainders of 2 and 5.
A.187
B.197
C.207
D.219
Answer: B.197
Explanation: Let 'N' is the smallest number which divided by 13 and 16 leaves respective remainders of 2 and 5.
Required number = (LCM of 13 and 16) - (common difference of divisors and remainders) = (208) - (11) = 197.
ANSWER:B
Question: Mike weighs twice as much as Mary. Mike's weight is 150% of Michelle's weight. Alan weighs 140% of Charlie's weight. Charlie weighs 180% of Mary's weight. Which of these 5 people weighs the highest?
A.Mary
B.Mike
C.Michelle
D.Alan
Answer: D.Alan
Explanation: Mary < Michelle < Mike
Charlie < Alan
Let x be Mary's weight.
Mike's weight is 2x and Alan's weight is 1.4*1.8x = 2.52x.
The answer is D.
Question: A train 210 m long, running with a speed of 63 km/hr will pass a tree in?
A.18 sec
B.16 sec
C.76 sec
D.12 sec
Answer: D.12 sec
Explanation: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 210 * 2/35 = 12 sec
Answer:D
Question: The average weight of 25 persons sitting in a boat had some value. A new person added to them whose weight was 46 kg only. Due to his arrival, the average weight of all the persons decreased by 5 kg. Find the average weight of first 25 persons?
A.2211
B.2721
C.227
D.176
Answer: D.176
Explanation: 25x + 46 = 26(x – 5)
x = 176
Answer:D
Question: There are 4 periods in each working day of a school. In how many ways can one organize 3 subjects such that each subject is allowed at least one period?
A.32
B.36
C.24
D.34
Answer: B.36
Explanation: 3 subjects can be arranged in 4 periods in 4P3 ways.
Remaining 1 period can be arranged in 3P1 ways.
Two subjects are alike in each of the arrangement. So we need to divide by 2! to avoid overcounting.
Total number of arrangements = (4p3 x 3P1)/2! = 36
ANSWER:B
Question: Which one of the following is not a prime number?
A.2
B.3
C.5
D.9
Answer: D.9
Explanation: 9 is divisible by 3. So, it is not a prime number.
Answer:D
Question: At a company, the average wage of male employees is $5 per hour, and the average wage of female employees is $8 per hour. If the average wage of all employees is $7.5 per hour, what is the ratio of the number of male employees to the number of female employees?
A.1 to 5
B.2 to 3
C.3 to 2
D.5 to 3
Answer: A.1 to 5
Explanation: Average hourly wage of male employees = 5 $
Average hourly wage of female employees = 8 $
Average hourly wage of all employees = 7.5 $
Let number of male employees = m
number of female employees = f
7.5 = (5m + 8f ) / m+f
=>7.5m + 7.5f = 5m + 8f
=> 2.5m = .5f
=> m/f = 2.5/.5 = 1/5
Answer A
Question: In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:
A.21/46
B.25/117
C.1/50
D.3/25
Answer: A.21/46
Explanation: Let S be the sample space and E be the event of selecting 1 girl and 2 boys.
Then, n(S)	= Number ways of selecting 3 students out of 25
= 25C3 `
=(25 x 24 x 23)/(3 x 2 x 1)
= 2300.
n(E)	= (10C1 x 15C2)
=10 x((15 x 14)	/(2 x 1))
= 1050.
P(E) =	n(E)/n(S)	=1050/2300=21/46
Option A
Question: A person X working alone can complete a work in 6 days. A person Y completes the same amount of work in 15 days, and a person Z when working alone can complete the same amount of work in 30 days. All three people work together for 2 days but then X and Y leave. How many more days does Z need to complete the work after X and Y leave?
A.12
B.13
C.14
D.15
Answer: C.14
Explanation: The fraction of work completed in two days is 2/6 + 2/15 + 2/30 = 16/30
The fraction of work remaining is 1 - 16/30 = 14/30
The number of days required for Z is 14 days.
The answer is C.
Question: A and B entered into partnership with capitals in the ratio 4 : 5. After 3 months, A withdrew 1/4 of his capital and B withdrew 1/5 of his capital. The gain at the end of 10 months was Rs. 760. A's share in this profit is:
A.Rs. 330
B.Rs. 360
C.Rs. 380
D.Rs. 430
Answer: A.Rs. 330
Explanation: If earlier their investmwnts were 4x and 5x for 3 months
and then
3x and 4x for next 7 months,
Then profit will be divided in ratio of (4x*3 + 3x*7) :( 5x*3+4x*7) or 33:43
Hence A's share in profit of Rs 760 = 760*33/76 = Rs 330.
ANSWER:A
Question: A student committee on academic integrity has 30 ways to select a president and vice president from a group of candidates. The same person cannot be both president and vice president. How many candidates are there?
A.7
B.8
C.9
D.6
Answer: D.6
Explanation: xC1 * (x-1)C1=30
x^2 -x -30 =0
(X-6) (X+5) = 0
X= 6 , -5
-5 can't possible.
D
Question: Three table runners have a combined area of 212 square inches. By overlapping the runners to cover 80% of a table of area 175 square inches, the area that is covered by exactly two layers of runner is 24 square inches. What is the area of the table that is covered with three layers of runner?
A. 18 square inches
B. 20 square inches
C. 24 square inches
D. 28 square inches
Answer: C. 24 square inches
Explanation: Total = a + b + c - (sum of EXACTLY 2-group overlaps) - 2*(all three) + Neither
80%*175 = 212 - 24 - 2*(all three) + 0
2*(all three) = 212 - 24 - 140
all three = 24
Answer: C
Question: The traffic lights at 3 different roads change after every 9 sec, 72 sec, 108 sec respectively. If they all change simultaneously at 9:15 AM then at what time will they again change simultaneously.
A.9:18:36
B.9:42:15
C.10:15:24
D.9:54:12
Answer: A.9:18:36
Explanation: LCM of 9,72,108 = 216 = 3mnts 36sec
The lines will change every 3m 36sec
The light will change again after 9:15 AM is = 9:15+0:03:36 = 9:18:36
Answer is A
Question: If 15% of 30% of 50% of a number is 108, then what is the number?
A.4000
B.3050
C.4400
D.4800
Answer: D.4800
Explanation: Let the number be a
Given, 15/100 * 30/100 * 50/100 * a = 108
=> 3/20 * 3/10 * 1/2 * a = 108
=> a = 10 * 20 * 10 * 2 = 4800.
ANSWER:D
Question: A bike covers a certain distance at the speed of 64km/h in 8 hrs. If the bike was to cover the same distance in approximately 6 hrs, at what approximate speed should the bike travel?
A.85 km/h
B.85.34 km/h
C.87.67 km/h
D.90.25 km/h
Answer: B.85.34 km/h
Explanation: Ans.(B)
Sol. Total distance = 64 × 8 = 512 km
Now speed = 512/6 = 85.34 km/h
Question: If P(A)=0.4, P(B)=0.6 and P(A ∪ B)=0.8. What is the value of P(A∩B')=?
A.0.1
B.0.2
C.0.3
D.0.4
Answer: B.0.2
Explanation: Solution:
P(A∪B) = P(A) + P(B) - P(A∩B') =>
0.8=0.4 - P(A∩B) =>P(A∩B)=0.2
P(A∩B') = P(A) - P(A∩B) = 0.4 - 0.2 = 0.2
Answer B
Question: 39 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?
A.10
B.13
C.14
D.15
Answer: B.13
Explanation: Let the required number of days be x.
Less persons, More days (Indirect Proportion)
More working hours per day, Less days (Indirect Proportion)
Persons 30	:	39 :: 12 : x
Working hours/day	6	:	5
Therefore 30 x 6 x x = 39 x 5 x 12
=> x =(39 x 5 x 12)/(30 x 6)
=> x = 13.
Correct answer is B
Question: How many three-digit integers between 310 and 400, exclusive, are divisible by 3 when the tens digit and the ones digit are switched?
A.3
B.19
C.30
D.22
Answer: C.30
Explanation: Answer is 30
No of digits between 310 and 400 (exclusive) = 400-310-1 = 89
No Intergers divisble by 3 =~ 89/3 ~ 30
Divsiblivity rule for 3 is Sum of all digits must be divisble by 3. It doesn't matter if ones digit and tens digits are switched.
e.g 372 is divisble by 3 (becae 3+7+2= 12 (divisble by 3))
switch digits 732 also divisble by 3 (becae 7+3+2= 12 (divisble by 3))
Divsiblivity rule for 3 is Sum of all digits must be divisble by 3. It doesn't matter if ones digit and tens digits are switched.
You have right. So it is enough to proceed like usual to find the numbers in a given range that are divisible by 3. So 399-312/3 +1 =30.
Answer : C
Question: A beats B by 20metres ,B beats C by20 metres in a 100 m race .By how much A beats C
A.35metres
B.36metres
C.37metres
D.38metres
Answer: B.36metres
Explanation: A : B = 100 : 80
B : C = 100 : 80
A : C = (A/B * B/C)
= (100/80 * 100/80)
= (100/64)
Therefore A beats C by = (100-64) = 36metres.
ANSWER:B