Easy 5 ! this box has the same length, width, and height as the 2 basketballs. which expression gives the volume of the empty space encircling the basketballs inside the box?

This one is easier to work out by elimination than by actual math:

1. We know it's a difference, therefore we need to subtract the volume of the balls from the volume of the box. B is wrong.

2. The box is 3dimensional so we must have 3 linear measurements multiplied together in it's volume calculation. D is wrong.

3. The sphere volume formula uses radius cubed (not diameter). C is wrong

A is the only one left and must be correct. 

To check:
Volume of the box:

Volume of two balls:

Total volume = box - balls:

This matches A, just as we thought.