DIRECTION for the question: Solve the following question and mark the best possible option.

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. After 10 hours, C is closed. In how much time will the tank be full?

A

16 hrs

B

13 hrs

C

12 hrs

D

18 hrs

E

20 hrs