RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: Bill has d animals, 12 of which were sold at a profit of 10% each while the rest were sold at a loss of 20% each. Overall, Bill made neither a profit nor a loss. Which of the following is equal to d?
A.6
B.12
C.18
D.24
Answer: C.18
Explanation: Total d animals, suppose each has price of x - total price = dx
now 12 were sold at profit of 10%, making equation - - 12*1.1x
now d-12 were sold at loss of 20%, making eqn --- (d-12)*0.8x
Now he made no profit or loss so,
dx = 12*1.1x + (d-12)*0.8x
solving for d, we get d=18
Ans C
Question: Jill, who lives in City C, plans to visit 2 different cities L, and S. She plans to visit each city exactly once and return to City C after the 2 visits. She can visit the cities in any order. In how many different orders can she visit the 2 cities?
A. 3
B. 2
C. 8
D. 9
Answer: B. 2
Explanation: 2! = 2=B
Question: The overall ages of Kumar, Hathim and Rahul is 93 years. 1 decade ago, the ratio of their ages was 2 : 3 : 4. What is the current age of Rahul?
A.38
B.37
C.34
D.35
Answer: A.38
Explanation: A
38
If the ages of Kumar, Hathim and Rahul 1 decade ago be 2A, 3A and 4A years correspondingly
Then, (2A + 10) + (3A + 10) + (4A + 10) = 93
9A = 93-30
9A = 63
A = 7
Rahul’s current age = (4A + 10)
= 38 years.
Question: A bus started its journey from Mumbai and reached Pune in 44min with its average speed of 50 km/hr. If the average speed of the bus is increased by 5km/hr, how much time will it take to cover the same distance?
A.30 min
B.35 min
C.37 min
D.40 min
Answer: D.40 min
Explanation: Sol. Distance between Ramgarh and Devgarh =(50*44)/60=110/3
Average speed of the bus is increased by 5 km/hr then the
speed of the bus = 55 km/hr
Required time = 110/3*60/55 = 40 min
D
Question: There are 12 pieces of radioactive metal V that look identical. 11 of the pieces give the same radiation count when measured, the 12th piece is a counterfeit and gives a different radiation level, which may be more or less than the other 11. We are given a radiation scale, which can take 2 sets of samples and compare their added up radiation levels to tell us if the sums are the same or if different, which set has the higher level of radiation. What is the minimum number of comparisons we need on this scale to identify the counterfeit sample and to also determine whether it has more or less radiation than the other samples ?
A.2
B.3
C.4
D.5
Answer: B.3
Explanation: First of all if you are down to just 3 pieces and you know that if the offending piece is less or more active, then it takes exactly 1 measurement to find out the offending piece. So you know you have to reduce the problem to three.
Now when you are down to either A or B after measurement 1, you need the next measurement to (a) reduce the problem set to 3 and (b) to know whether anser is more or less. Now you cannot compare a group of 4 to 4, as in the best case it will only reduce the problem to 4 elements which is not good enough.
If you have to choose a set of 3 to compare, you cannot pick any 3 on the same side from the same set (A or B) because if you do this, a quick check will show you that in every choice there is a case where you can only get down to 4 elements. Eg. If you weighed {1,2,3} v/s {5,9,10} and they were equal you're problem would only reduce to {4,6,7,8}
The easiest way to solve this then is to compare 3 to 3, and make sure each side has elements from both AB such that whatever the measurement outcome in the worst case the problem reduces to 3 elements only. Which is why the sets {1,5,9} and {2,6,7} OR {A,B,C}{A,B,B}. The extra element from C is just taken to make the problem symmetric so to say, we have 8 elements and we make it 9, to compose 3 sets of 3 each.=B
Question: On dividing a number by 48, we get 29 as remainder. On dividing the same number by 8, what will be the remainder ?
A.2
B.3
C.4
D.5
Answer: D.5
Explanation: Number=48x+29 (∵ since the number gives 29 as remainder on dividing by 48)
=(6×8×x)+(3×8)+5
Hence, if the number is divided by 8, we will get 5 as remainder.
ANSWER:D
Question: The difference of 2 digit number & the number obtained by interchanging the digits is 36. What is the difference the sum and the number if the ratio between the digits of the number is 1:2 ?
A.6
B.8
C.12
D.14
Answer: B.8
Explanation: Let the number be xy.
Given xy – yx = 36.
This means the number is greater is than the number got on reversing the digits.
This shows that the ten’s digit x > unit digit y.
Also given ratio between digits is 1 : 2 => x = 2y
(10x + y) – (10y +x) = 36 => x – y = 4 => 2y – y =4.
Hence, (x + y) – (x – y) = 3y – y = 2y = 8
B
Question: If a solid sphere of radius 10 cms is moulded into 8 spherical solid balls of equal radius, then surface area of each ball (in cm2) is?
A.100
B.728
C.278
D.168
Answer: A.100
Explanation: 4/3 π * 10 * 10 * 10
= 8 * 4/3 πr3
r = 5
4π * 5 * 5
= 100π
Answer: A
Question: what is the value of (5)^-5?
A.1/3125
B.1/3000
C.1/658
D.1/500
Answer: A.1/3125
Explanation: 5^-5= 1/(5)^5= 1/3125
ANSWER:A
Question: How many four letter words are formed using the letters of the word POLICE?
A.280
B.321
C.330
D.360
Answer: D.360
Explanation: The number of letters in the given word is four.
The number of three letter words that can be formed using these four letters is 6P4
= 6 * 5 * 4 * 3 = 360.
Answer: D
Question: We bought a total of 80 books at the store. Math books cost $4 and history books cost $5. The total price was $390. How many math books did we buy?
A.10
B.20
C.30
D.40
Answer: A.10
Explanation: M + H = 80
H = 80 - M
4M + 5H = 390
4M + 5*(80 - M) = 390
M = 10
The answer is A.
Question: The cost price of a radio is Rs.1500 and it was sold for Rs.1230, find the loss %?
A.18%
B.17%
C.78%
D.14%
Answer: A.18%
Explanation: 1500 ---- 270
100 ---- ? => 18%
Answer: A
Question: A certain sum becomes Rs. 20720 in four years and 24080 in six years at simple interest. Find sum and rate of interest?
A.11
B.12
C.44
D.66
Answer: B.12
Explanation: :
Let the interest for one year be x.
As amount = Principal + Interest, we have
P + 4x = 20720 --- (1) ; P + 6x = 24080 --- (2)
Solving the equations (1) and (2), we can get
P = Rs. 14000 and x = Rs. 1680
Interest for one year on Rs. 14000 is Rs. 1680
So, R = (100 * 1680)/(14000 * 1) = 12% p.a.Answer: B
Question: The cost of raw material of a product increases by 30, the manufacturing cost increases by 20 and the selling price of the product increases by 60. The raw material and the manufacturing cost, originally, formed 40 and 60 of the total cost respectively. If the original profit was one-fourth the original manufacturing cost, find the approximation new profit percentage.
A.48.38%
B.54.68%
C.62.48%
D.42.36%
Answer: A.48.38%
Explanation: Explanation :
Let, the total initial cost of the product be Rs 100.
Manufacturing cost = Rs 60
Raw materials cost = Rs 40
Also, original selling price
=> Rs100+(60/4)= Rs 115.
New raw material cost
=>Rs 40+30% of 40= Rs 52.
New manufacturing cost
=>Rs 60+20% of 60= Rs 72
New cost of the product = Rs124
New selling price
=>115+60% of 115=Rs 184
New profit percentage
=>60/124×100
=>48.38%.
Answer : A
Question: The students of a particular class were given two tests for evaluation. Twenty Five percent of the class cleared both the tests and forty five percent of the students were able to clear the first test.
You have to calculate the percentage of those students who passed the first test and were also able to pass the second test. How will you do it?
A.50 %
B.60 %
C.70 %
D.80 %
Answer: B.60 %
Explanation: Solution:
60%
Explanation:
In all such cases where you have to find out the probability of anything with an already given situation, you have to use the formula for conditional probability.
In this case, you have to find out the probability that the second test was passed by a student given that he passed the first test already.
Therefore, P(Second/First) = P (First and Second)/ P (First)
= 0.25/0.42
=0.60
=60 %
Answer B
Question: Find the number of square tiles to cover the floor of a room measuring 3 m * 9 m leaving 0.25 m space around the room. A side of square tile is given to be 25 cms?
A.340
B.476
C.472
D.471
Answer: A.340
Explanation: 2 1/2 * 8 1/2 = 1/4 * 1/4 * x => x
= 340
Answer:A
Question: The ratio of boys to girls in Class A is 3 to 4. The ratio of boys to girls in Class B is 3 to 5. If the two classes were combined, the ratio of boys to girls in the combined class would be 17 to 22. If Class A has one more boy and two more girls than class B, how many girls are in Class A?
A.8
B.9
C.10
D.11
Answer: A.8
Explanation: Since it is given that the ratio of boys to girls in Class A is 3 to 4 - so we can quickly eliminate the answer choices which are not multiples of 4.
so ans can either be 8 0r 12.
With 8 as answer - no of girls = 8
With 12 as answer - no of girls = 12
Now Class A has one more boy and two more girls than class B and also the ratio of boys to girls in Class B is 4 to 5.
So we are looking for number of girls in B to be divisible by 5.
With 8 as answer -> Girls = 8-2 = 6. (Not possible)
With 12 as answer -> Girls = 12-2 = 5.
So, answer = 8. ( A)
Question: An investment T gained an interest payment of $250 each month when the annual interest rate was 8%, how much more should we invest annually if we want to gain 12% more per month with a new annual interest rate of 7.5% ?
A.$9,360
B.$9,100
C.$8,250
D.$7,300
Answer: D.$7,300
Explanation: Answer is D : 7,300
An investment T gained an interest payment of $250 each month when the annual interest rate was 8%,Interest per annum with 8% interest rate is = 250* 12 = Principal * Interest Rate(8/100)
This gives Principal as 37,500$
For an revised interest of 12% more and new interest rate of 7.5% , ie. 250* 12 * 1.12 = Principal * Interest Rate (7.5/100)
This gives the new Principal as 44,800.
The question is how much more should we invest, so 44,800 - 37,500 = 7,300.D
Question: A side of beef lost 35 percent of its weight in processing. If the side of beef weighed 550 pounds after processing, how many pounds did it weigh before processing?
A. 191
B. 355
C. 737
D. 846
Answer: D. 846
Explanation: Let weight of side of beef before processing = x
(65/100)*x = 550
=> x = (550 * 100)/65 = 846
Answer D
Question: Two stations A and B are 110 km apart on a straight line. One train starts from A at 6 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?
A.9 a.m
B.10 a.m
C.12 a.m
D.02 a.m
Answer: A.9 a.m
Explanation: Suppose they meet x hours after 6 a.m.
Distance covered by A in x hours = 20x km.
Distance covered by B in (x - 1) hours = 25(x - 1) km.
Therefore 20x + 25(x - 1) = 110
45x = 135
x = 3.
So, they meet at 9 a.m.
Answer:A
Question: A began business with Rs.45000 and was joined afterwards by B with Rs.5400. When did B join if the profits at the end of the year were divided in the ratio of 2:1?
A.8
B.2
C.7
D.5
Answer: C.7
Explanation: 45*12 : 54*x = 2: 1
x = 5
12 -5 = 7
Answer: C
Question: The ratio of sodium chloride to ammonium in 100 kg of mixed ammonium normally used by three chemists is 3: 14. The amount of sodium chloride to be added to 100 kg of mixed ammonium to make the ratio 9 :25 is
A.12 kg
B.6.625 kg
C.6.25 kg
D.6.35 kg
Answer: A.12 kg
Explanation: sodium chloride in 100 kg = 3/17 x 100 = 17.64 kg
ammonium in 100 kg = 14/17 x 100 = 82.35 kg
Now 82.35 is 25 parts out of (25 + 9) = 34 parts.
Hence 9 parts = 9/25 x 82.35 =29.64
Amount to be added = 29.64 - 17.64= 12 Kg
ANSWER:A
Question: John had a stock of 1300 books in his bookshop. He sold 75 on Monday, 50 on Tuesday, 64 on Wednesday, 78 on Thursday and 135 on Friday. What percentage of the books were not sold?
A.50.4%
B.23.8%
C.66.5%
D.69.0%
Answer: D.69.0%
Explanation: Let N be the total number of books sold. Hence
N = 75 + 50 + 64 + 78 + 135 = 402
Let M be the books NOT sold
M = 1300 - N = 1300 - 402 = 898
Percentage
Books not sold / total number of books = 898/1300 = 0.69 = 69%
correct answer D
Question: What is the difference between the local values of 8 in the number 58408?
A.2992
B.7992
C.2877
D.2077
Answer: B.7992
Explanation: Explanation:
8000 â€“ 8 = 7992
Answer:B
Question: 1297 x 1297 = ?
A.A)1682209
B.B)1951601
C.C)1951602
D.D)1951603
Answer: A.A)1682209
Explanation: 1297 x 1297	= (1297)2
= (1300 - 3)2
= (1300)2 + (3)2 - (2 x 1300 x 3)
= 1690000 + 9 - 7800
= 1690009 - 7800
= 1682209.
Answer:A
Question: A dice is rolled 3 times. After each roll, the number on the top of the dice's face is noted. How many 3 digit numbers can be formed?
A.6
B.18
C.3
D.108
Answer: D.108
Explanation: A dice has 6 sides. First roll can give us any of the 6 sides on the top. So first number can be any of the six (1,2,3,4,5,6)
Similarly for the second roll, any of the six sides can turn up. So second number can be any of the six (1,2,3,4,5,6)
Same for the 3rd roll, 3rd number can be any of the six.
Total 3 digit numbers that can turn up are 6 * 6 * 6 = 108
Answer: D
Question: The number of arrangements that can be made with the letters of the word MEADOWS so that the vowels occupy the even places?
A.720
B.144
C.20
D.36
Answer: B.144
Explanation: The word MEADOWS has 7 letters of which 3 are vowels.
-V-V-V-
As the vowels have to occupy even places, they can be arranged in the 3 even places in 3! i.e., 6 ways. While the consonants can be arranged among themselves in the remaining 4 places in 4! i.e., 24 ways.
Hence the total ways are 24 * 6 = 144.
Answer: Option B
Question: A building contractor employs 20 male, 15 female and 5 child workers. To a male worker he pays Rs.25 per day, to a female worker Rs.20 per day and a child worker Rs.8 per day. The average wage per day paid by the contractor is?
A.12
B.21
C.87
D.16
Answer: B.21
Explanation: 20 15 5
25 20 8
500 + 300 + 40
= 840/40
= 21
Answer:B
Question: The banker's discount of a certain sum of money is Rs. 36 and the true discount on the same sum for the same time is Rs. 30. What is the sum due?
A.Rs. 180
B.Rs. 120
C.Rs. 220
D.Rs. 200
Answer: A.Rs. 180
Explanation: Explanation :
F = (BD ×TD)/(BD – TD)=(36×30)/(36–30)=(36×30)/6=36×5 = Rs. 180 Answer : Option A
Question: In a class, the average age of 30 boys is 13 years and the average of 20 girls is 12 years. what is the average age of the whole class?
A.12
B.12.6
C.13
D.13.34
Answer: B.12.6
Explanation: Total age of 50 students
(30X 13+20 X 12) = 630
Average = 630/50 = 12.6 Years
B
Question: If x, y, and z are consecutive positive integers greater than 1, not necessarily in that order, then which of the following is (are) true?
I. x > z
II. 2x+ 2y > 2z
III. yz > xz
IV. xy > y + z
A. I only
B. II only
C. II and III only
D. II and IV only
Answer: B. II only
Explanation: we do not know the values or the relative values but that the three are consecutive..
so the max difference in any two number is 2 and min 1..
lets see the choices..
I. x > z...
we do not know the values or the relative values... need not be true..
II. 2x+ 2y > 2z or x+ y > z
we take the worst case that z is teh largest and x and y are lowest possible..... so 2+3>4.. 5>4.. always true
III. yz > xz
we do not know the values or the relative values between x and y..need not be true
IV. xy > y + z
xy-y>z or y(x-1)>z...
again lets take the worst scenario..
we take the worst case that z is the largest and x and y are lowest possible..... so (2-1)3>4.. 3>4.. not true
only ii is true
ans B
Question: How many digits in the number '5279143' will be as far away from the beginning of the number as when the digits are rearranged in ascending order from left to right within the number?
A.8
B.1
C.4
D.6
Answer: B.1
Explanation: Answer: Option B
Question: The octahedron is an eight-faced geometric solid that can be thought of as two square-based pyramids with the squares glued together. All eight faces of the octahedron are congruent equilateral triangles. Given that an edge is where the side of one equilateral triangles is attached to the side of another equilateral triangle, how many edges does the octahedron have?
A.8
B.10
C.12
D.16
Answer: C.12
Explanation: Again, we will use the analogy of Earth’s geography to orient us. (This, in and of itself, is a useful trick to remember.) When we glue together the two square faces, call that the “square equator” of the octagon. That’s a square, so obviously it have four edges. The pyramid above that goes up to a “north pole vertex”, and four edges run down that vertex to the corners of the “square equator,” so that’s four more. Similarly and symmetrically, the upside-down pyramid underneath comes to a point at the “south pole vertex”, with an additional four edges running from that vertex to the “square equator.” That’s four edges on the “square equator”, four more above, four more below, for a total of twelve edges on the octahedron. Answer = C
Question: A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:
A.45 km/hr
B.50 km/hr
C.54 km/hr
D.55 km/hr
Answer: B.50 km/hr
Explanation: Explanation:
Speed of the train relative to man = 125/10	m/sec
= 25/2	m/sec
= 25/2	x	18/5	km/hr
= 45 km/hr.
Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
x - 5 = 45 x = 50 km/hr.
ANSWER IS B
Question: Divide $ 1162 among A, B, C in the ratio 35 : 28 : 20.
A.490,490,490
B.360,392,460
C.490,392,280
D.260,160,60
Answer: C.490,392,280
Explanation: Sum of ratio terms = (35 + 28 + 20) = 83.
A's share = $ (1162 x (35/83))= $ 490; B's share = $ (1162 x(28/83))= $. 392;
C's share = $ (1162 x (20/83))= $ 280.
ANSWER C 490,392,280
Question: In a ratio which is equal to 7:9, if the antecedent is 56, then the consequent is?
A.72
B.85
C.64
D.51
Answer: A.72
Explanation: We have 7/9 = 56/x
7x = 56*9
x = 72
consequent = 72
Answer is A
Question: The speed at which a man can row a boat in still water is 24 kmph. If he rows downstream, where the speed of current is 8 kmph, what time will he take to cover 40 metres?
A.4.49 seconds
B.8.89 seconds
C.26 seconds
D.12 seconds
Answer: A.4.49 seconds
Explanation: Speed of the boat downstream = 24+ 8
= 32 kmph
= 32 * 5/18 = 8.89 m/s
Hence time taken to cover 40 m = 40/8.89
= 4.49 seconds.
Answer:A
Question: Ramu rides his bike at an average speed of 45 km/hr and reaches his desitination in four hours. Somu covers the same distance in six hours. If Ramu covered his journey at an average speed which was 9 km/hr less and Somu covered his journey at an average speed which was 10 km/hr more, then the difference in their times taken to reach the destination would be (in minutes).
A.10 minutes
B.20 minutes
C.40 minutes
D.30 minutes
Answer: D.30 minutes
Explanation: D
30 minutes
Distance travelled by Ramu = 45 * 4 = 180 km
Somu travelled the same distance in 6 hours.
His speed = 180/6 = 30 km/hr
Hence in the conditional case, Ramu's speed = 45 - 9 = 36 km/hr and Somu's speed = 30 + 10 = 40km/hr.
Therefore travel time of Ramu and Somu would be 5 hours and 4.5 hours respectively. Hence difference in the time taken = 0.5 hours = 30 minutes.
Question: A is two years older than B who is twice as old as C. If the total of the ages of A, B and C be 72, then how old is B?
A.28 years
B.19 years
C.29 years
D.10 years
Answer: A.28 years
Explanation: Let C's age be x years.
Then, B's age = 2x years.
A's age = (2x + 2) years.
(2x + 2) + 2x + x = 72
5x = 70 => x = 14
Hence, B's age = 2x = 28 years.
Answer: A
Question: A man gains 60% by selling an article for a certain price. If he sells it at double the price, the percentage of profit will be.
A.130%
B.320%
C.150%
D.160%
Answer: B.320%
Explanation: Explanation:
Let the C.P. = x,
Then S.P. = (160/100)x = 8x/5
New S.P. = 2(8x/5) = 16x/5
Profit = 16x/5 - x = 16x/5
Profit% = (Profit/C.P.) * 100
=> (16x/5) * (1/x) * 100 = 320 %
Option B
Question: Find out the wrong term in the series 2, 10, 20, 200, 4000, 6000
A.8000
B.80,000
C.6000
D.800,000
Answer: D.800,000
Explanation: Explanation:
Each number with in the series is the product of the two numbers that proceed it.
So, if (10 * 20 = 200) , then (200 * 4000 = 800000). 800,000 should replace 6000.
Answer: D) 800,000
Question: The average marks of a class of 30 students is 50 and that of another class of 50 students is 60. Find the average marks of all the students?
A.56.25
B.52.9
C.52.1
D.52.3
Answer: A.56.25
Explanation: Sum of the marks for the class of 30 students = 30 * 50 = 1500
Sum of the marks for the class of 50 students = 50 * 60 = 3000
Sum of the marks for the class of 80 students =
1500 + 3000 = 4500
Average marks of all the students = 4500/80
= 56.25
Answer:A
Question: Ammu is 9 years older than Surya, and Jacob is four times older than Ammu. If S is Surya’s age and J is Jacob’s age, what is the relationship between S and J?
A.J = 4S + 10
B.J = 4S + 26
C.J = 4S + 5
D.J = 4S + 36
Answer: D.J = 4S + 36
Explanation: A=S+9 and J=4A --> J=4S+36
Answer D
Question: Simplify: 1398 x 1398
A.1954404
B.1945404
C.1954044
D.1954440
Answer: A.1954404
Explanation: = 1398 x 1398 - (1398)^2 = (1400 - 2)^2= (1400)^2 + (2)^2 - 2 x 1400 x 2
=1960000 + 4 - 5600 = 1954404.
Answer is A.
Question: A boat can travel with a speed of 15 km/hr in still water. If the speed of the stream is 5 km/hr. find the time taken by the boat to go 68 km downstream?
A.2 hours
B.3 hours
C.4 hours
D.3 hours 24 minutes
Answer: D.3 hours 24 minutes
Explanation: Solution
Speed Downstream	= (15 + 5) km/hr
= 20 km/hr.
Time taken to travel 68 km downstream	=(68 / 20)hrs
= 3 hrs 24 minutes.
Answer D
Question: Priya, Harini and Kalyani's pets costs Rs. 6000, Rs. 4000 and Rs. 8000 respectively. An addition of Rs. 300 tax added to Harini's pet cost. The difference between the tax costs of Priya and Kalyani is?
A.180
B.150
C.250
D.500
Answer: B.150
Explanation: Pet costs of Priya, Harini and Kalyani is 6000 : 4000 : 8000 = 3 : 2 : 4
And also given that, tax of Harini's pet is Rs. 300
=> 2 parts out of 9 parts is Rs. 300
Now, required difference is 4 - 3 = 1 part
Required difference = 1/2 (300) = Rs. 150.Answer: B
Question: There are 10000 students in the particular school out of that 60% students are like science subject and of these , 20% are also like maths.If 20% of the students who like science and maths are girls students.then find out the number of girls student who like maths and science?
A.300
B.120
C.240
D.280
Answer: C.240
Explanation: total number of students=10000; Out of these 60% like science subject are =6000; Out of these 20% like maths subject=1200 ; out of these 1200 students 20% students are girls= 240
Question: A fair price shopkeeper takes 10% profit on his goods. He lost 70% goods during theft. His loss percent is:
A.72%
B.42%
C.32%
D.67%
Answer: D.67%
Explanation: Explanation:
Suppose he has 100 items. Let C.P. of each item be Re. 1.
Total cost = Rs. 100. Number of items left after theft = 30.
S.P. of each item = Rs. 1.10
Total sale = 1.10 * 30 = Rs. 33
Hence, loss % = 67/100 * 100 = 67%
Answer:D
Question: A circular rim 28 inches in a diameter rotates the same number of inches per second as a circular rim 35 inches in diameter. If the smaller rim makes C revilutions per second, how many revilutions per minute does the larger rim makes in terms of C?
A.a) 48pi/C
B.b) 75m
C.c) 48C
D.d) 24C
Answer: C.c) 48C
Explanation: distance covered by a circular wheel per sec* = 2*pi* r * n
where n is number of revolution
So we know the smaller rim makes C rev per sec so the inches coverd SR per sec = 28 * pi* C
the problem the say SR rotates the same number of inches as the LR.
The inches covered by the LR per sec = 35 * pi*Y
So equate both u will get Y = 4/5 C
Theis is in sec we need the answer in min so 48C
answer is C
Question: Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
A.19 1/7 min
B.15 1/7 min
C.17 1/7 min
D.7 1/7 min
Answer: C.17 1/7 min
Explanation: 1/20 + 1/30 - 1/40 = 7/120
120/7 = 17 1/7
ANSWER:C