Correct, the answer is B.
-4 - (-36) = -4 + 36 = 32 units
I think it would be 23 bags without any cookies left over
You can express the edge lengths in terms of "cubes" or you divide the total volume by the volume of a cube. It works either way.
Edge lengths are
.. 80 cubes by 8 cutes by 13 cubes
so total volume is
.. (80 * 8 * 13) = 8320 cubes
In cubic inches, the volume is
.. (20 in)*(2 in)*(3 1/4 in) = 130 in^3.
The volume of a 1/4-in cube is (1/4 in)^3 = 1/64 in^3.
Then the number of cubes that will fit in the prism is
.. (130 in^3)/(1/64 in^3) = 8320 . . . . cubes
8320 cubes are needed to fill the rectangular prism.
