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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.

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

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:

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 - A funnel can discharge a tank in 40 minutes. A second pipe with distance across twice as much as that of the first is likewise joined with the tank to purge it. The two together can exhaust the tank in:

Answer : B

Explanation

A pipe with double diameter will take half time.
So, the second pipe can empty the full tank in 20 min.
Part emptied by both in 1 min. (1/40+ 1/20) = 3/40
Time taken to empty the full tank = 40/3 min.

Q 4 - Two channels can fill a tank in 15 hours and 12 hours separately and a third pipe can purge it in 4 hours. In the event that the channels are opened all together at 8 am, 9 am and 11am separately, the tank will be exhausted at

Answer : D

Explanation

Let the tank be emptied in x hrs after 8 am.
Work done by A in x hrs, by B in (x-1) hrs and C in (x-3) hrs = 0
⇒x/15+ (x-1)/12- (x-3)/4 = 0 ⇒ 4x+5(x-1) - 15(x-3) = 0
⇒6x= 40 ⇒x= 20/3 hrs.
⇒x= 6 hrs. 40 min after 8 am
Hence the tank will be emptied at 14 hrs 40 min, i.e., 2:40 pm

Q 5 - A tank is fitted with two taps A and B. A can fill the tank totally in 45 minutes and B can purge the full tank in 60 minutes. On the off chance that both the taps are opened on the other hand for 1 minute, then in what amount of time the unfilled tank will be filled totally?

Answer : D

Explanation

Work done by A in 1st minutes and B 2nd minute= (1/45- 1/60)= 1/180
Part filled in 2 min = 1/180
Part filled in 358 min = (1/360*358) =   358/360 = 179/180
Remaining part = (1-179/180) = 1/180
1/45 part is filled by A in (45*1/180) min= 1/4 min.
Total time taken to fill it = 358 1/4 min = 5 hrs.58 min 15 sec.

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?

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?

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 - A cistern has 3 pipes A, B and C. A and B can ill it in 3 hours and 4 hours respectively while C can empty the completely filled cistern in 1 hour. If the pipes are opened in order at 3, 4 and 5 pm respectively, at what time will the cistern be empty?

Answer : A

Explanation

In 2 hours Pipe A will fill = 2/3 tank
In 1 hour Pipe B will fill = 1/4 tank
Part of tank filled till 5 PM = (2/3) + (1/4)
= 11/12

Remaining part = 1 - (11/12)
= 1/12

Net part emptied when A, b and C are opened = (1/3) +( 1/4) - 1
= (4+3-12)/12
=  -5/12
∴ 5/12 part is emptied in 1 hour.
∴ 11/12 is emptied in (12/5)*(11/12) = 11/5
= 2 hr 12 min
∴ Tank will be emptied at 7:12 PM.

Q 9 - A pump can fill a tank with water in 2 hours. Because of a leak in the tank, it takes 7/3 hours to fill the tank. The leak can empty the filled tank in?

Answer : D

Explanation

Part of the tank filled by the pump in 1 hour = 1/2
Part of the tank filled by the pump in 1 hour because of the leak = 3/7
∴ Part of the tank emptied by the leak in 1 hour = 1/2 - 3/7
= 1/14
∴ Leak will empty the tank in 14 hours.

Q 10 - Two pipes can fill a tank in 12 hours and 15 hours respectively. A third pipe can empty it in 20 hours. If the tank is empty and all the three pipes are opened, then the tank will be full in (in hour) ?

Answer : C

Explanation

Part of tank filled by both the pipes in 1 hour = 1/12 + 1/15
= 3/20
Part of tank emptied by third pipe in 1 hour = 1/20
∴ Part of tank filled when all the pipes are opened simultaneously = 3/20 - 1/20
= 2/20
= 1/10
∴ Tank will be filled in 10 hours.

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