Question (23/28)
Pipe A and B can fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all 3 pipes are opened together, then tank will be filled in how many hours ?(A)  A
(B)  B
(C)  C
(D)  D
Question (24/28)
Pipe A can fill tank in 5 hours, pipe B in 10 hours and pipe C in 30 hours. If all the pipes are open, in how many hours will the tank be filled ?(A)  2 Hours
(B)  2.5 Hours
(C)  3 Hours
(D)  3.5 Hours