what are the possible dimensions of a rectangular prism with a volume of 40 cubic inches

Answer 1

assuming you want integer values, just pick out 3 sets of the factors of 40, which are
1,2,2,2,5
Make sure you have used up all 5 factors when you are done.
For example, you might choose
1*(2x2x2)*5 = 1x8x5
You can use 1 as many times as you need.

Answer 2

Can you just tell us the answer?