Pretty sure the answer is F=4 2/3 I think
The exact formula for surface area for a rectangular prism is 2lw+2lh+2wh. Where l=length. W=width.h=height.
V=72 because you need to divide both sides by 2 which makes it v=72
20% of what is 36....
0.20x = 36
x = 36 / 0.20
x = 180 <== total price