Question

The volumes of two cubes are in the ratio $8:27$. The ratio of their surface areas is :

• A. $2:3$
• B. $4:9$
• C. $12:9$
• D. None of these

Answer 1

The correct option is B $4:9$

In volume of cube we have ratio as :

$\frac{a_1^3}{a_2^3}=\frac{8}{27}$

$\therefore \frac{a_1}{a_2}=\frac{2}{3}$

So, in case of surface area we have ratio as :

$\frac{a_1^2}{a_2^2}=\frac{2^2}{3^2}$

$=\frac{4}{9}$