Pipes and Cistern

1.		Two pipes A and B can fill a cistern in 12 minutes and 15 minutes respectively while a third pipe C can empty the filled tank in 6 minutes. Pipe A and pipe B are kept open for 5 minutes in the beginning and then pipe C is also opened. In what time the cistern will be emptied ?

30 min

33 1/3 min

40 min

45 min

2.		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

3.		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

4.		Two pipes A and B can fill a tank in 36 min and 45 min respectively. A pipe C can empty the full tank in 30 min. First A and B are opened and after 7 minutes, pipe C is also opened. In how much time, the tank will be full ?

46 min

48 min

50 min

52 min

5.		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

6.		A pipe A can fill a tank four times as fast as another pipe B. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone can fill the tank in:

180 min

160 min

144 min

136 min

7.		Two pipes A and B can fill a tank in 6 hours and 4 hours respectively . If they are opened on alternate hours and if pipe A is opened first in how many hours the tank will be filled ?

4

4.5

5

6

8.		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

9.		Two taps A and B can fill a tank separately in 10 minutes and 20 minutes respectively. However, a leakage at the bottom can empty a filled tank in 40 minutes. How much time will both the taps alongwith the leakage take to fill the empty tank ?

8 minutes

9 minutes

10 minutes

32 minutes

10.		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