A solid rectangular metal box of 8 inches long, 2 inches wide and 4 inches deep is melted down. All the liquid metal is used to case a cube. What is the length of one side of the cube?

Find the volume of the rectangle:

8 x 2 x 4 = 64 cubic inches.

This means the square can have a volume of 64 cubic inches.

The formula for the volume of a square is V = S^# where S is the length of the side.

Replace V with 64 to solve for S:

64 = S^3

To find S, take the cubic root of 64:

S = ∛64

S = 4

The length of a side is 4 inches.