Question

A rectangle prism has length of 20 inches, a width of 2 inches and height of 3 1/4 inches. The prism is filled with cubes that have edge lengths of 1/4 inches. How many cubes are needed to fill the rectangle?

Answer 1

The first thing we must do is find the volume of the rectangular prism which will be given by:
Vtotal = (20) * (2) * (3 1/4)
Votal = 130 in ^ 3
We now look for the volume of each individual cube:
Vcube = (1/4) ^ 3
Vcube = 1/64 in ^ 3
The number of cubes will be:
N = (Vtotal) / (Vcube)
N = (130) / (1/64)
N = 8320
Answer:
to fill the rectangle are needed 8320 cubes