Question

If each edge of cube is doubled, its surface area will increase by

• A. $2$ times
• B. $3$ times
• C. $4$ times
• D. $5$ times

Answer 1

Answer: (C)

$4$ times

Let the edge of the cube be $x$ units

$\therefore$ Surface area of cube $=6x^2$ sq. units

When the edge is doubled, the new length $=2x$ units

$\therefore$ New surface area of cube $=6\times (2x{)}^2$ $=24x^2$ sq. units

So, increase in surface area $=\frac{24x^2}{6x^2}=4$ times

So, option C is correct.