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 - Two funnels can fill a tank in 20 minutes and 30 minutes separately. On the off chance that both the channels are opened at the same time, then the tank will be filled in:
Part filled by both pipes in 1 min. =(1/20+ 1/30)= 5/60 = 1/12
Time taken to fill the tank = 12 minutes
Q 2 - A channels can fill a tank in x hours and another funnel can exhaust it in y (y>x) hours. In the event that both the funnels are open, in how long will the tank be filled?
Work done by filling pipe in 1 hr = 1/x
Work done by emptying pipe in 1 hr = 1/y
Net filling work done by both in 1 hr = (1/x- 1/y) = (y-x)/xy
∴The tank will be filled in xy/(y-x) hrs.
Q 3 - A storage has two funnels. One can fill it with water in 8hours and the other can exhaust it in 5 hours. In how long will the reservoir be purged if both the channels are opened together when 3/4 of the storage is now loaded with water?
Net part emptied by both in 1 hr = (1/5-1/8)= 3/40
3/40 part is emptied in 1 hr.
3/4 part will be emptied in (40/3*3/4) hrs = 10 hrs.
Q 4 - Two pipes A and B can fill a tank in 15 minutes and 20 minutes separately. Both the channels are opened together. Be that as it may, following 4 minutes, pipe is turned off. What is the aggregate time required to fill the tank?
Part filled by both in 4 min. = 4*(1/15+1/20)= (4*7/60)= 7/15
Part unfilled = (1-7/15) = 8/15
1/20 part is filled by B in 1 min.
8/15 part is filled by B in (20*8/15) min. = 32/3 min = 10 min 40 sec.
Total time taken = (4 min+10 min 40 sec.) = 14 min 40 sec.
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?
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 - Three funnels A, B; C can fill a tank in 6 hours. In the wake of working at it together for 2 hours, C is shut and A and B can fill the remaining part in 7 hours. The quantity of hours taken by C alone to fill the tank is:
Part filled by (A+B+c) in 2 hours= (1/6*2)=1/3
2/3 part is filled by (A+B) in 7 hours.
Whole is filled by (A+B) in (7*3/2) hr=21/2hrs.
Part filled by C in 1 hour = (1/6-2/21) = 3/42 = 1/14
∴C alone can fill it in 14 hours.
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?
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?
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.
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 - 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, the slower pipe alone will be able to fill the tank in ?
Let the time taken by faster pipe be x min
∴ 1/x + 1/3x = 1/36
Or, (3 +1)/3x = 1/36
Or, x = 48 min
∴ Time taken by slower pipe to fill the tank = 3*48min = 144 min
