If the height is equal to 2 m and the width is twice the height then, the height is equal to 4 m. Also, since the length is twice the width, the width is 8 m. The volume is the product of these three dimensions giving us an answer of 64 m³. The volume of the cube with sides equal to 1 m is 1m³. Thus, the greatest number of cubes that will fit into the given rectangular prism is also 64.