Given :
Solid 1:
The side of the cube is, a = 8 cm.
Solid 3:
The side of the cube is, b = 4 cm.
The volume of the third cube can be calculate as,
The volume of first cube is,
Thus, the ratio can be calculated as,
Thus the required ratio is 8:1.
Since the volume is proprtional to the cube of the side, the ratio will also be in the range of cube of the fractional difference between the sides.