Question

If the lateral surface area of a cube is 1600 $c{m}^2$ then its edge is

• A. $15cm$
• B. $18cm$
• C. $20cm$
• D. $24cm$

Answer 1

The correct option is C $20cm$

Lateral surface area of a cube$=4a^2$

$\Rightarrow 4a^2=1600$

$\Rightarrow a^2=\frac{1600}{4}$

$\Rightarrow a^2=400$

$\Rightarrow a=\sqrt{400}$

$\Rightarrow a=20cm$