Pipes and Cistern - Quantitative Aptitude (MCQ) questions

1)   A cistern is filled by Pipe A and Pipe B together in 2.4 hours. Pipe A alone can fill the cistern at the rate of 100 litres per hour. Pipe B alone can fill the cistern in 4 hours. What is the capacity of the cistern?
- Published on 13 Apr 17

a. 1200 litres
b. 600 litres
c. 1000 litres
d. 500 litres
Answer  Explanation 

ANSWER: 600 litres

Explanation:
pipes and cisterns


2)   There is a leak at the bottom of a cistern. Due to this it takes 8 hours to fill the cistern. Had there not been a leak, it would take one hour less to fill the cistern. How much time does it take for the leak to completely empty the cistern?
- Published on 12 Apr 17

a. 48 hours
b. 55(1/3) hours
c. 56 hours
d. 15 hours
Answer  Explanation 

ANSWER: 56 hours

Explanation:
pipes and cisterns


3)   Tap P alone fills a cistern in 2 hours; while tap Q alone fills the same cistern in 3 hours. A new tap R is attached to the bottom of the cistern which can empty the completely filled cistern in 6 hours. Sunny started all three taps together at 9am. When will the tank be full?
- Published on 11 Apr 17

a. 10.30 am
b. 11.15 am
c. 12 pm
d. 9.45 am
Answer  Explanation 

ANSWER: 10.30 am

Explanation:
pipes and cisterns


4)   A cistern can be filled in 6 hours by taps P and Q. If tap R also joins them, then cistern is filled in 5 hours. Tap P can fill the cistern at twice the rate of tap Q. In what time tap Q and R fill the cistern?
- Published on 11 Apr 17

a. 9.75 hours
b. 10. 90 hours
c. 11.25 hours
d. 12.90 hours
Answer  Explanation 

ANSWER: 11.25 hours

Explanation:
pipes and cisterns


5)   A cistern is normally filled with water in 10 hours but takes 5 hours longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty the cistern in
- Published on 11 Apr 17

a. 20 hours
b. 40 hours
c. 50 hours
d. 30 hours
Answer  Explanation 

ANSWER: 30 hours

Explanation:
pipes and cisterns


6)   A tank has three taps P, Q and R. Taps P and Q can fill the tank in 1.5 and 2 hours, respectively. Tap R can empty the completely filled tank in just half hour. Tap P is opened at 8 am, tap Q is opened at 9am and tap R is opened at 10 am. At what exact time will the tank be empty?
- Published on 17 Mar 17

a. 12 pm
b. 1.25 pm
c. 12.12 pm
d. 12.28 pm
Answer  Explanation 

ANSWER: 12.12 pm

Explanation:
pipes and cisterns


7)   A pipe can fill a tank in 6 hours. Another pipe can empty the tank in 12 hours. If both pipes are opened simultaneously, the part of tank filled by both pipes in 1 hour is?
- Published on 17 Mar 17

a. 1/9 th part
b. 1/6 th part
c. 1/12 th part
d. 1/3 rd part
Answer  Explanation 

ANSWER: 1/12 th part

Explanation:
pipes and cisterns


8)   A tap having diameter 'd' can empty a tank in 84 min. How long another tap having diameter '2d' take to empty the same tank?
- Published on 15 Mar 17

a. 21 minutes
b. 42 minutes
c. 168 minutes
d. 28 minutes
Answer  Explanation 

ANSWER: 21 minutes

Explanation:
pipes and cisterns


9)   Pipe A can fill a tank 5 times faster than Pipe B and takes 32 minutes less than Pipe B to fill the tank. If both the pipes are opened together, then in how much time the tank would be full?
- Published on 15 Mar 17

a. 32/3 minutes
b. 32/5 minutes
c. 20/3 minutes
d. 5/32 minutes
Answer  Explanation 

ANSWER: 20/3 minutes

Explanation:
pipes and cisterns


10)   Two pipes M and N can fill a tank in 22.5 and 15 minutes, respectively. If both the pipes are opened simultaneously, after how much time should N be closed so that the tank is full in 18 minutes?
- Published on 15 Mar 17

a. 4 minutes
b. 3 minutes
c. 4.5 minutes
d. 2.5 minutes
Answer  Explanation 

ANSWER: 3 minutes

Explanation:
pipes and cisterns


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