Answer:
64
Explanation:
If you measure the cubes inside for the length, width and height, you get:
Length - 5 cubes
Width -5 cubes
Height - 3 cubes
The volume of the prism is 5 * 5 * 3 = 75. This means the prism can hold a total of 75 cubes
The amount of cubes already in there is 11
so 75 - 11= 64