Two pipes A and B can fill a cistern in 120 minutes and 150 minutes respectively. There is also an outlet C. If all the three pipes are opened together, the cistern gets filled in 100 minutes. How much time will be taken by C to empty full tank?

Two pipes A and B can fill a cistern in 120 minutes and 150 minutes re

1.	Two pipes A and B can fill a cistern in 120 minutes and 150 minutes respectively. There is also an outlet C. If all the three pipes are opened together, the cistern gets filled in 100 minutes. How much time will be taken by C to empty full tank?
A.	3 h 20 min
B.	2 h 40 min
C.	3 h
D.	3 h 40 min
Answer» B. 2 h 40 min