Two taps X and Y together can fill a tank in 36 hours, Y and Z in 48 hours and X and Z in 72 hours. If all the three taps are opened, then in how much time (in hours) the tank will be completely filled?

Two taps X and Y together can fill a tank in 36 hours, Y and Z in 48 h

1.	Two taps X and Y together can fill a tank in 36 hours, Y and Z in 48 hours and X and Z in 72 hours. If all the three taps are opened, then in how much time (in hours) the tank will be completely filled?
A.	16
B.	32
C.	22
D.	36
Answer» C. 22