Two pipes A and B can fill a tank in 18 and 36 hours respectively. An outlet pipe C can empty it in 24 hours. If they opened together, then in how many hours the 3/4th of the capacity of the tank is filled?

Two pipes A and B can fill a tank in 18 and 36 hours respectively. An

1.	Two pipes A and B can fill a tank in 18 and 36 hours respectively. An outlet pipe C can empty it in 24 hours. If they opened together, then in how many hours the 3/4th of the capacity of the tank is filled?
A.	22 hours
B.	24 hours
C.	16 hours
D.	20 hours
E.	18 hours
Answer» F.