5,760 in.3 (cubed)
To calculate the volume, you multiply the length by the width by the height.
40 inches x 12 inches x 24 inches = 11,520 cubic inches
However, since the desk has two legs that create an empty space in the middle, you must subtract the volume of the empty space.
The empty space is 10 inches (width) x 4 inches (height) x 18 inches (depth) = 720 cubic inches.
11,520 - 720 = 10,800 cubic inches or 5,760 in.3.