Two cylindrical water tanks stand side by side. One has a radius of meters and contains water to a depth of meters. The other has a radius of meters and is empty. Water is pumped from the first tank to the second tank at a rate of cubic meters per minute. How long to the nearest tenth of a minute, must the pump run before the depth of the water is the same in both tanks?

Source: NCTM Mathematics Teacher, January 2006

**SOLUTION**

Let represent the same depth of water in each tank. The sum of the volumes in each tank equals the original volume in the first tank.

Simplify

Volume that is transferred to the second tank

Time it takes to transfer the water

minutes

**Answer**: minutes