Filling a tank. A water tank has an inlet pipe and a drain pipe. A full tank can be emptied in 30 minutes if the drain is opened and an empty tank can be filled in 45 minutes with the inlet pipe opened. If both pipes are accidentally opened when the tank is full, then how long will it take to empty the tank?
In one minute the inlet pipe puts in 1/45 of the tank.
In one ...
This solution shows how to set up the word problem algebraically and the brief calculations for determining the time it takes to empty the tank.