Top 100 Aptitude Questions and Answers for Competitive Exams

Pipes and Cisterns Problems 

Q.51. Two pipes A and B can separately fill a cistern in 60 minutes and 75 minutes respectively. There is a third pipe in the bottom of the cistern to empty it. If all the tree pipes are simultaneously opened, then the cistern is full in 50 minutes. In how much time the third pipe alone can empty the cistern?

(A) 80 min

(B) 100 min

(C) 110 min

(D) 120 min

Q.52. A Cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously then after how much time will the cistern get filled?

(A) 4.5 hrs

(B) 5 hrs

(C) 6.5 hrs

(D) 7.2 hrs

Q.53. A pump can fill a tank with water in 2 hours. Because of a leak, it took   hours to fill the tank. The leak can drain all the water of the tank in:

(A) hrs

(B) 8 hrs

(C) 10 hrs

(D) 14 hrs

Q.54. A tap can fill a tank in 6 hours. After the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

(A) 3 hrs

(B) 3 hrs 45 min

(C) 4 hrs

(D) 5 hrs 15.

Q.55. One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in :

(A) 80 min

(B) 108 min

(C) 144 min

(D 180 min

Q.56. A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?

(A) 6 min to empty

(B) 6 min to fill

(C) 8min to empty

(D) 8 min to fill

(E) None of these

Q.57. A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?

(A) 15 hrs

(B) 25 hrs

(C) 35 hrs

(D)45

(E) None of these

Q.58. Pipe A can fill a tank in 5 hours, pipe B in 10 hours and pipe C in 30 hours. If all the pipes are open, in how many hours will the tank be filled?

(A) 1

(B) 2.5

(C) 3

(D) 3.5

Q.59. A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is:

(A) 6 hrs

(B) 12 hrs

(C) 15 hrs

(D) 30 hrs

Q.60. Pipes A and B can fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the tree pipe are opened together, then the tank will be filled in:

(A)   hours

(B)   hours

(C)   hours

(D)   hours