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:

A. 10 min

B. 12 min

C. 14 min

D. 16 min

Explanation:

Coming soon. Refer Important Points for the method to solve such questions.

2. Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three pipes are opened at the same time?

A. 19 1/7 min

B. 18 1/7 min

C. 17 1/7 min

D. 16 1/7 min

Explanation:

Coming soon. Refer Important Points for the method to solve such questions.

3. 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:

A. 13 1/3 hours

B. 10 hours

C. 12 hours

D. 14 hours

Explanation:

Coming soon. Refer Important Points for the method to solve such questions.

4. 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 ?

A. 6 min. to empty

B. 6 min. to fill

C. 9 min. to empty

D. 9 min. to fill

Explanation:

Coming soon. Refer Important Points for the method to solve such questions.

5. 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 ?

A. 30 min

B. 33 1/3 min

C. 40 min

D. 45 min