Question

Pipe a can fill tank in 20 minutes, b can empty empty iy in 25 minutes. If both are opened simultaneously then at what time tank will be filled

Answer 1

Answer:

Pipe A can filled in 1 minutes = 1/20 part of the tank. Pipe B can emptied in 1 minutes = 1/30 part of the tank. If the taps are opened alternatively, then tank will be filled in 2 minutes = 1/20 - 1/30 = 1/60 parts of the tank. Hence 1/60 parts are filled in 2 minutes.