A solid cube of side 12cm is cut into eight cubes of equal volume. What will be the side of the new cube?

Given: Side 12cm ⇒ Volume of cube = 12 × 12 × 12 = 1728cm³ ⇒ Volume of smaller cube = 1/8 of 1728 = (1/8) × 1728 = 216cm³ ⇒ Let side be S. ∴(S)³ = 216 ⇒ S = 6cm
Ratio of SA of cubes = SA of bigger cube / SA of smaller cube = (12/6)² = 2²/1 = 4/1 ∴Ratio between their surface areas 4:1