# A water tank can be filled by an inlet pipe in 8 hours. It takes twice that long for the outlet pipe to empty the tank. How long will it take to fill the tank if both pipes are open?

##### 1 Answer

Aug 31, 2017

If both pipes are open, it fills the tank in

#### Explanation:

Inlet pipe fills water tank in

Outlet pipe empties the tank in

therefore, outlet pipe empties half the tank in

therefore, if both pipes are open in

Hence, if both pipes are open, it fills the tank in