Question

a rectangular prism is completely packed with 84 cubes of edge length 1 over 3 inch without any gap or overlap

Answer 1

The volume of a cube is s^3, where s is the length of a side.

If you have 84 cubes with sides of 1/3 in, the total volume is:

V=84(1/3)^3 in^3

V=84/27 in^3

V=28/9 in^3

V≈3.11 in^3  (to nearest hundredth of a cubic inch)