Pipes and Cistern MCQs for Competitive Examination
Solve the following problems.
Q. 1
Two pipes A and B can separately fill a tank in 2 hours and 3 hours respectively. If both the pipes are opened simultaneously in the empty tank, then the tank will be filled in
(A) 1 hour 12 minutes
(B) 2 hours 30 minutes
(C) 1 hour 15 minutes
(D) 1 hour 20 minutes
Answer: (A) 1 hour 12 minutes
Explanation: N/A
Q. 2
Two pipes A and B can fill a tank in 36 minutes and 45 minutes respectively. Another pipe C can empty the tank in 30 minutes. First A and B are opened. After 7 minutes, C is also opened. The tank is filled up in
(A) 39 minutes
(B) 46 minutes
(C) 40 minutes
(D) 45 minutes
Answer: (B) 46 minutes
Explanation: N/A
Q. 3
Two pipes X and Y can fill a cistern in 24 minutes and 32 minutes respectively. If both the pipes are opened together, then after how much time (in minutes) should Y be closed so that the tank is full in 18 minutes?
(A) 10
(B) 8
(C) 6
(D) 5
Answer: (B) 8
Explanation: N/A
Q. 4
If two pipes function simultaneously, a tank is filled in 12 hours. One pipe fills the tank 10 hours faster than the other. How many hours does the faster pipe alone take to fill the tank?
(A) 20 hours
(B) 18 hours
(C) 15 hours
(D) 12 hours
Answer: (A) 20 hours
Explanation: N/A
Q. 5
Three taps A, B, C can fill an overhead tank in 4, 6 and 12 hours respectively. How long would the three taps take to fill the tank if all of them are opened together?
(A) 2
(B) 3
(C) 4
(D) 5
Answer: (A) 2 hours
Explanation: N/A
Q. 6
Two pipes A and B can fill a cistern in 3 hours and 5 hours respectively. Pipe C can empty in 2 hours. If all the three pipes are open, in how many hours the cistern will be full?
(A) Can’t be filled
(B) 10 hours
(C) 15 hours
(D) 30 hours
Answer: (D) 30 hours
Explanation: N/A
Q. 7
Two pipes, P and Q together can fill a cistern in 20 minutes and P alone can in 30 minutes. Then Q alone can fill the cistern in
(A) 62
(B) 60
(C) 61
(D) 51
Answer: (B) 60
Explanation: N/A
Q. 8
One tap can fill a water tank in 40 minutes and another tap can make the filled tank empty in 60 minutes. If both the taps are open, in how many hours will the empty tank be filled?
(A) 2 hours
(B) 2.5 hours
(C) 3 hours
(D) 3.5 hours
Answer: (A) 2 hours
Explanation: N/A
Q. 9
Three taps A, B, and C together can fill an empty cistern in 10 minutes. The tap A alone can fill it in 30 minutes and the tap B alone in 40 minutes. How long will the tap C alone take to fill it?
(A) 16
(B) 24
(C) 32
(D) 40
Answer: (B) 24
Explanation: N/A
Q. 10
Two pipes can fill a cistern separately in 10 hours and 15 hours. They can together fill the cistern in
(A) 6 hours
(B) 7 hours
(C) 8 hours
(D) 9 hours
Answer: (A) 6 hours
Explanation: N/A
Q. 11
Two pipes A and B can fill a tank with water in 30 minutes and 45 minutes respectively. The water pipe C can empty the tank in 36 minutes. First A and B are opened. After 12 minutes C is opened. Total time (in minutes) in which the tank will be filled up is
(A) 12
(B) 30
(C) 36
(D) 24
Answer: (D) 24
Explanation: N/A
Q. 12
Three pipes A, B, and C can fill a tank in 6 hours, 9 hours, and 12 hours respectively. B and C are opened for half an hour, then A is also opened. The time taken by the three pipes together to fill the remaining part of the tank is
(A) 3
(B) 2
(C) 2(1/2)
(D) 3(1/3)
Answer: (C) 2(1/2)
Explanation: N/A
Q. 13
There are two pumps to fill a tank with water. The first pump can fill the empty tank in 8 hours, while the second in 10 hours. If both the pumps are opened at the same time and kept open for 4 hours, the part of the tank that will be filled up is
(A) 9/10
(B) 1/10
(C) 2/5
(D) 1/5
Answer: (A) 9/10
Explanation: N/A
Q. 14
If 3/5th of a cistern is filled in 1 minute, the time needed to fill the rest is
(A) 40 sec
(B) 36 sec
(C) 30 sec
(D) 24 sec
Answer: (A) 40 sec
Explanation: N/A
Q. 15
A pipe can fill a tank in 24 hours. Due to a leakage in the bottom it is filled in 36 hrs. If the tank is half full, then how much time will the leak take to empty the tank?
(A) 48 hours
(B) 72 hours
(C) 36 hours
(D) 24 hours
Answer: (C) 24 hours
Explanation: N/A
Q. 16
Three pipes A, B and C can fill a tank in 6 hours. After working together for 2 hours, the pipe C is closed and A and B fill the tank in 8 hours. The time (in hours) in which the tank can be filed by pipe C alone is
(A) 10
(B) 12
(C) 8
(D) 9
Answer: (B) 12
Explanation: N/A
Q. 17
Pipe A can fill a cistern in 6 hours and pipe B can fill in 8 hours. Both the pipes are opened simultaneously, but after two hours pipe A is closed. How many hours will B take to fill the remaining part of the cistern?
(A) 2
(B) 3(1/3)
(C) 4
(D) 2(2/3)
Answer: (B) 3(1/3)
Explanation: N/A
Q. 18
Pipes A and B can fill a tank in 8 hrs and 12 hrs, whereas pipe C can empty the tank in 6 hrs. A and B are opened for 3 hrs and then closed and C is opened instantly. C will empty the tank in
(A) 9/2 hours
(B) 15/4 hours
(C) 9/4 hours
(D) 7/2 hours
Answer: (B) 15/4
Explanation: N/A
Q. 19
Pipe X can fill a tank in 20 hours and Pipe Y can fill the tank in 35 hours. Both the pipes are opened on alternate hours. Pipe Y is opened first, then in how much time (in hours) the tank will be full?
(A) 269/11
(B) 280/11
(C) 179/7
(D) 172/7
Answer: (C) 179/7
Explanation: N/A
Q. 20
Two taps P and Q can fill a tank in 24 hours and 18 hours respectively. If the two taps are opened at 11 a.m., then at what time (in p.m.) should the tap P be closed to completely fill the tank at exactly 2 a.m.?
(A) 5
(B) 2
(C) 3
(D) 4
Answer: (C) 3
Explanation: N/A