Question

If each edge of a cube is doubled, how many times will its surface area increase?
[2 marks]

Answer 1

Let the edge of cube be $l$
Since, the surface are of the cube $\left(A\right)$ = $6l^2$
[1 mark]
When the edge of cube is doubled, then the surface area of the cube $\left(A^{\prime }\right)=6(2l{)}^2$
$=6\times 4l^2$
$=4\times 6l^2$
$=4\times A$

Hence, the surface area will increase 4 times.
[1 mark]