Pipes and Cistern - Quantitative Aptitude (MCQ) questions

1)   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


2)   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


3)   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


4)   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


5)   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


6)   Two pipes M and N are opened together to fill a tank. Both the pipes fill the tank in time X minutes. When M alone is filling the tank, it takes 9 minutes more time than X to fill the tank. In a similar manner N takes 16 minutes more time than X to fill the tank. What is the value of X?
- Published on 10 Mar 17

a. 12 minutes
b. 7 minutes
c. 25 minutes
d. 144 minutes
Answer  Explanation 

ANSWER: 12 minutes

Explanation:
pipes and cisterns


7)   Pipe P can fill a tank in 38 hours. Pipe Q alone can fill it in 19 hours. Pipe R can empty the full tank in 133 hours. If all the pipes are opened together, how much time will be needed to make the tank full?
- Published on 10 Mar 17

a. 28 hours
b. 95 hours
c. 19 hours
d. 14 hours
Answer  Explanation 

ANSWER: 14 hours

Explanation:
pipes and cisterns


8)   Two pipes M and N can fill a pool in 40 minutes and 60 minutes, respectively. The entire pool can completely be emptied by another pipe P in 30 minutes. M, N and P are opened alternatively and each is kept open for just 1 minute. In how much time will the pool be filled?
- Published on 10 Mar 17

a. 180 minutes
b. 167 minutes
c. 177 minutes
d. 165 minutes
Answer  Explanation 

ANSWER: 167 minutes

Explanation:
pipes and cisterns


9)   A tap can fill a tub in 24 hours. Due to a leak at the bottom of the tub, the tap fills the tub in 36 hours. If the tub is full, how much time will the leak take to empty it?
- Published on 10 Mar 17

a. 72 hours
b. 48 hours
c. 60 hours
d. 96 hours
Answer  Explanation 

ANSWER: 72 hours

Explanation:
pipes and cisterns


10)   3 pipes have diameters 2 cms, 3 cms and 4 cms. The ratio of water flowing through them is equal to ratio of the square of their diameters. The biggest pipe when open alone, can fill the entire pool in just 126 minutes. When all the pipes are opened together, the pool would be filled in how much time?
- Published on 05 Mar 17

a. 2016/29 minutes
b. 2111/126 minutes
c. 215/63 minutes
d. 155 minutes
Answer  Explanation 

ANSWER: 2016/29 minutes

Explanation:
pipes and cisterns


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