Mary has 50 earring boxes. The boxes measure 1 inch on each side. How many rectangular prisms, each with different-sized base, could Mary make by stacking all the earring boxes?

Since each earring box has a side of 1 inch, that means each one has a volume of 1 cu. inch. Thus, 50 cubes combined will have a volume of 50 cu. inches. That means, that the prism must have a volume of 50 cu. inches. Since for prism, the volume is L (W) (H), we can list down the possible trios that will have a product of 50. Note that 50 = 1 x 2 x 5 x 5 and hence, we can group these and come up with the following list of factor: {1, 2, 25}, {1, 10, 5}, {2, 5, 5} Therefore, there are 3 possible prisms that can be formed using the cubes. The answer is 3.