Question

The ratio of volume and total surface area of a solid sphere is 8 : 1, then value of radius = cm.

• A. 2
• B. 24
• C. 64

Answer 1

The correct option is B 24

Volume of a sphere = $\frac{4}{3}\pi r^3$
Total surface area of a sphere = $4\pi$$r^2$
$\Rightarrow$ $\frac{Volume}{Surfacearea}=\frac{\frac{4}{3}\pi r^3}{4\pi r^2}=\frac{8}{1}$
$\Rightarrow \frac{r}{3}=8$
$\Rightarrow r=24cm$