A cubical water tank has each edge 5m long. Find the volume of water in the tank if 1/5th of the tank is empty.

Pls help...
Urgent***

3 answers

volume if full = 5^3 = ...
but 1/5 is empty, so ?? is filled with water

water = ?? * 5^3 = ....
Answer is 100m^3
Pls help