A cubical water tank with edges measuring 10 feet in length is initially full of water. If the tank were then to lose water at a constant rate of 10 cubic feet per second, in how many seconds would the tank be full?

100 secs

Explanation:

edge of the cubical tank = 10 feet

volume of the cube is = edge^3

therefore volume = 10^3 = 1000 cubic feet

discharge from the pipe Q = 10 cubic feet per second

time taken to fill the tank t = V/Q = 1000/10 = 100 secs