Most of you are making a BIG mistake. The correct answer is B but many of you are incorrectly justifying your answer choice.
In this scenario, you can't multiply the dimensions of the box to attain the total volume and then divide that number by the volume of the rectangular box to determine the total number of blocks that could fit. That's wrong.
For example, I could ask what is the total number of rectangular blocks (10x2x1) that fit in a rectangular box of (5x4x1).
Do you see the problem? With the method most of you are using, your answer to this question would be 1 block. However, while both volumes equal 20 cubic units, you can't fit a rectangular block with side length 10 into a box with side length 5 no matter how you try.
The correct way of approaching this problem is demonstrated by Brunel:
Bunuel wrote:
(2) The inside dimensions of box X are 60 centimeters by 30 centimeters by 20 centimeters --> we have the dimensions of the little boxes as well as the dimensions of box X (basically we have all the info we could possibly knew), hence we can calculate the maximum # of boxes that will fit inside box X, no matter what this # actually is. Sufficient.
Do NOT make this mistake on test day.