Pipes and Cistern

1.		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

2.		Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. The total time required to fill the tankis:

10 min 40 sec

12 min 40 sec

14 min 40 sec

16 min 40 sec

3.		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

4.		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

5.		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

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

120 min

136 min

144 min

150 min

7.		A pump can fill a tank in 2 hours but due to a leak, it took 2 1/3 hours to fill the tank. The leak can empty the tank in:

13 1/3 hours

10 hours

12 hours

14 hours

8.		Two pipes A and B can separately fill a cistern in 60 minutes and 75 minutes respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are opened simultaneously then the cistern is filled in 50 minutes. The third pipe alone can empty the cistern in:

90 min

100 min

110 min

120 min

9.		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

10.		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