Question

The dimensions of a cube are doubled. By how many times will its volume and surface area increase ?

Answer 1

Let the side of the original cube be s
Then side of the new cube = 2s


(i) Volume of original cube = s × s × s = $s^3$ cubic units
Volume of new cube = 2s × 2s × 2s = $8s^3$ cubic units
$\therefore$ Volume increases eight times if the side is doubled.
(ii) Surface area of original cube = $6s^2$
Surface area of new cube = $6\left(2\right)s^2=24s^2=4\left(6s^2\right)$


$\therefore$ Surface area increases four times.