If all the sides of a prism are multiplied by 5, by what factor does the volume increase?

I'd say increasing each side by 5 increases the volume by a factor of 125 because 5*5*5 = 125.

Example:

A 4*5*6 prism has a volume of 120

Increasing each side by a factor of five

(20*25*30) = 15,000

15,000 / 120 = 125