Question

A tank is filled by intake pipe in 2 hours and emptied by outlet pipe in 4 hours,If both pipes are opened,how long will it take to fill the tank?

Answer 1

Answer:

2 hours taken to intake

So in 1 hour 1/2

4 hours taken to outlet

So in 1 hour 1/4

When both the pipes are opened together they work in opposition.

So, 1/2-1/4

Ans is 4 hours taken to fill