Pipes and Cistern

1.		Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are opened together, the tank will be filled in:

10 min

12 min

14 min

16 min

2.		A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely ?

6 min. to empty

6 min. to fill

9 min. to empty

9 min. to fill

3.		Two pipes can fill a tank in 20 minutes and 24 minutes respectively and a waste pipe can empty 3 litres per minute. All he three pipes working together can fill the tank in 15 minutes. The capacity of the tank is:

80 litres

100 litres

120 litres

180 litres

4.		Two pipes A and B can fill a tank in 12 minutes and 15 minutes respectively. If both the pipes are opened simultaneously, and the pipe A is closed after 3 minutes, then how much more time will it take to fill the tank by pipe B ?

7 min 15 sec

7 min 45 sec

8 min 15 sec

8 min 45 sec

5.		Two pipes A and B can fill a tank in 9 hours and 3 hours respectively. If they are opened on alternate hours and if pipe A is opened first, how many hours, the tank will be filled?

4 hr

5 hr

5.5 hr

6 hr

6.		Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, the pipe B would have taker 6 hours more than pipe A to fill the cistern. pipe A can fill the cistern separately in:

1 hrs

2 hrs

6 hrs

4 hrs

7.		Two pipes, A and B, can fill a tank in 60 minutes and 40 minutes respectively. How many minutes will it take to fill the tank from empty state if pipe B is used for half the time and pipe A and pipe B fill it together for the other half ?

20 min

25 min

27 min

30 min

8.		A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?

30 hours

32 hours

35 hours

40 hours

9.		Two pipes A and B can fill a tank in 15 hours and 20 hours respectively while a third pipe C can empty the full tank in 25 hours. All the three pipes are opened in the beginning but after 10 hours, pipe C is closed. In how much time, the tank will be filled ?

12 hrs

13 hrs

14 hrs

15 hrs

10.		Two taps A and B can fill a tank in 5 hours and 20 hours respectively. If both the taps are open then due to a leakage it took 30 minutes more to fill the tank. In what time will the leakage alone empty the full tank ?

24 hrs

27 hrs

30 hrs

36 hrs