After decreasing the sidelength to 20% of the original size, the new sidelength is:
[tex]0.20a[/tex]
The volume of a cube is given by the product of 3 of its sidelengths, it means, that the volume of the cube is the sidelength raised to 3:
[tex]V=(0.20a)^3=0.008a^3[/tex]
