The volume is calculated by multiplying the length x width x height. So the volume of this box is 30 cm3.
Assuming the cube is 1 x 1 x 1 (volume= 1cm3), then 30 cubes would be able to fit into the box. (30/1 = 30)
However, if the cube is 2x2x2, it would be able to fit 8 cubes.