Question

If the diagonal of cube is $\sqrt{300}$ cms, then the surface area (in sq. cm) is

• A. $300$
• B. $600$
• C. $1200$
• D. $2400$

Answer 1

Answer: (B)

$600$

If each side of the cube $=$ $a$ cm, then
length of a diagonal $=$ $a\sqrt{3}$ cm, surface area $=6a^2.$
Since $a\sqrt{3}=\sqrt{300}$
Therefore, $a=10$ and surface area $=6a^2=600$