Question

What is the percentage increase in the surface area of a cube when each side is doubled to the original value?

• A. $25\%$
• B. $50\%$
• C. $150\%$
• D. $300\%$

Answer 1

Answer: (D)

$300\%$

Let each edge of cube be '$a$'. Then, its surface area $S={6a}^2$

New edge $=2a$

New surface area, $S^1=6\times {\left(2a\right)}^2=24a^2$

% increase $=\frac{{24a}^2-{6a}^2}{{6a}^2}\times 100=300$%