Arusha draws a rectangular prism that is made up of 2 connected cubes, each with side length e. the surface area of a certain rectangular prism with edge length e is represented by the formula sa = 10e (squared), and the volume of the prism is represented by the formula v = 2e (cubed).
a: what is the surface area of the prism if its edge length is 5 cm?
b: arusha plans to build the prism and partially fill it with 150 cubic cm of sand. what fraction of the prism's volume will be filed by the sand?