Aptitude - Pipes & Cisterns Online Quiz



Following quiz provides Multiple Choice Questions (MCQs) related to Pipes & Cisterns. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - In 1 minute 3/7 of a basin is filled. Whatever remains of the container can be filled in:

A - 2 min

B - 4/3 min

C - 7/3 min

D - none of these

Answer : B

Explanation

Part filled in 1 min. = 3/7. remaining part = (1- 3/7)= 4/7
Let the required time be x min.
More part, more time taken. (Direct)
3/7: 4/7:: 1: x ⇒ 3x/7 = (4/7*1) ⇒ x= 4/3 min.

Q 2 - A tank can be filled by a tap in 20 minutes and by another tap in an hour. Both the taps are kept open for 10 minutes and after that the first tap is shutoff. After this, the tank will be totally filled in:

A - 10 min

B - 12 min

C - 15 min

D - 20 min

Answer : D

Explanation

Part of the tank filled by both in 10 min. = 10*(1/20+1/60)= 40/60 = 2/3
Remaining part = (1-2/3) = 1/3
1/60 part is now filled in 1 min.
1/3 part is now filled in (60*1/3) min. = 20 min.

Q 3 - Pipes A and B can fill a tank in 20 hours and 30 hours separately and channel C can purge the full tank in 40 hours. In the event that every one of the funnels is opened together, what amount of the reality of the situation will become obvious eventually expected to make the tank full?

A - 73/7 hours

B - 64/5 hours

C - 120/7 hours

D - 77/4 hours

Answer : C

Explanation

Net part filled in 1 hr = (1/20+ 1/30 ? 1/40)= 7/120
Time needed to make the tank full = 120/7 hrs.

Q 4 - Two funnels can fill a reservoir in 14hrs and 16 hrs. individually. The funnels are opened all the while and it is found that because of spillage in the last, 32 minutes additional are taken for the reservoir to be topped off. In the event that the storage is full, in what time would the release unfilled it?

A - 96 hours

B - 102 hours

C - 106 hours

D - 112 hours

Answer : D

Explanation

Work done by two pipes in 1 hr= (1/14+1/16)= 15/112
Total time taken by two pipes and leak in 1 hr= (112/15+32/60) hrs= 8 hrs.
Work done by the leak in 1 hr = (15/112- 1/8) = 1/112
Hence, the leak will empty the full cistern in 112 hrs.

Q 5 - A reservoir has three channels A, B and C. A and B can fill it in 3 hrs and 4 hrs. individually while C can exhaust the totally filled reservoir in 1 hours. On the off chance that the funnels are opened all together at 3 pm, 4 pm and 5 pm individually, at what the truth will surface eventually reservoir void?

A - 6.15 pm

B - 7.12 pm

C - 8.12 pm

D - 8.35 pm

Answer : B

Explanation

Let the cistern be emptied in x hrs after 3 pm
Work done by A in x hrs, by B in(x-1) hrs and by C in (x-2) hrs= 0
⇒x/3 +x-1/4 ? (x-2) =0 ⇒ 4x+3(x-1)-12(x-2) = 0
⇒5x=21 ⇒x= 4 hrs 12 min.
Required time is 7.12 pm.

Q 6 - A tap can fill a tank in 6 hours. After a large portion of the tank is filled, three more comparable taps are opened. What is the aggregate time taken to fill the tank totally?

A - 3hrs 15 min.

B - 3 hrs 45 min.

C - 4 hrs

D - 4 hrs 15 min

Answer : B

Explanation

Time taken by the tap to make the tank half full= 3 hrs.
Remaining part = 1/2
Part filled by 4 taps in 1 hour= (4*1/6) = 2/3
2/3 part is filled in 1 hour.
1/2 part is filled in (3/2*1/2) hr = 3/4 hr = 45 min.
Required time = 3hrs 45 min.

Q 7 - A storage has a hole which would exhaust it in 8 hours. A tap is transformed on which concedes 6 liters a moment into the reservoir and it is currently purged in 12 hours. What number of liters does the reservoir hold?

A - 7580 ltr.

B - 7960 ltr.

C - 8290 ltr.

D - 8640 ltr.

Answer : D

Explanation

Part filled in 1 hour = (1/8- 1/12)= 1/24
Time taken to fill the cistern= 24 hours
Water moved in it 24 hours = (6*60*24) = 8640 liters.
Capacity of the cistern = 8640 liters.

Q 8 - Pipes A and B can fill a tank in 10 hours each. A third pipe C empties the tank in 20 hours. If all the three pipes are opened simultaneously, in how much time will the tank be filled?

A - 6 hr 30 min

B - 6 hr 40 min

C - 6 hr 20 min

D - 4 hr 40 min

Answer : B

Explanation

Net part filled in 1 hour = (1/10 + 1/10 - 1/20)
= (2+2-1) /20
= 3/20
∴ Tank will be full in 20/3 = 18/3 hours
= 6 hr 40 min

Q 9 - A cistern has two pipes. One can fill it with water in 8 hours and the other can empty it in 5 hours. In how many hours will the cistern be emptied if the both the pipes are opened together when 3/4 of the cistern is already full of water.

A - 13.5 hours

B - 10 hours

C - 6 hours

D - 3.5 hours

Answer : B

Explanation

Part if cistern emptied in 1 hour = 1/5 - 1/8
= 3/40
3/40 part is emptied in hour.
∴ 3/4 part is emptied in 40/3 * 3/4 = 10 hour

Q 10 - Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for 1 hour each alternatively, the tank will be full in -

A - 5 hr

B - 7.5 hr

C - 6 hr

D - 7 hr

Answer : D

Explanation

Tank filled by (A+B) in 1 hour = (1/12 + 1/15) = 3/20
Tank filled by (A+C) in 1 hr = (1/12 + 1/20) = 2/15

∴ Part of tank filled in 2 hr = (3/20 + 2/15) = 17/60
∴ Part of tank filled in 6 hr = (3*17/60) = 17/20

Remaining part = 1 - 17/20 = 3/20

Now it is the turn of A and B and 3/20 is filled by A and B in 1 hour.

∴ Total time taken to fill the tank = (6+1) = 7 hr
aptitude_pipes_cisterns.htm
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