Two taps J and K can fill the tank alone in 30 and 20 hours respectively. If they are opened together, in how many hours will the tank be filled?

Two taps J and K can fill the tank alone in 30 and 20 hours respective

1.	Two taps J and K can fill the tank alone in 30 and 20 hours respectively. If they are opened together, in how many hours will the tank be filled?
A.	12
B.	24
C.	48
D.	16
Answer» B. 24