Question

A pipe can fill a cistern in 45 minute and waste pipe empties it in one hour if both the pipes are opened at the same time, in how many hours will the cistern be filled?​

Answer 1

Answer:

Given:

Time is taken to pipe A to fill a tank = 45 minutes

Time is taken to the pipe to empty a tank = 30 mins

Calculations:

In one minute pipe, a can fill tank = 1/45th part of the tank

In one-minute pipe B can Empty tank = 1/30th part of the tanks

Work is done by a and together = (1/45) + (-1/30) (∵ Empty a tank is negative work)

⇒ (1/45) - (1/30) = (2 - 3)/90 = - 1/90

∴ The work done in negative the tank never be fills

In pipes and cisterns, the time taken to empty a tank is less than time is taken to fill a tank then tank never be fills