Answer:
840 cubes
Explanation:
First we need to find the volume of each one:
Rectangular prism: Volume = 10.5 * 5 * 2 = 105 in3
Cube: Volume = 0.5 * 0.5 * 0.5 = 0.125 in3
Now, to find how many cubes can fit inside the prism, we just need to divide the volume of the prism by the volume of the cube:
Number of cubes = 105 / 0.125 = 840 cubes