Question

If volume and surface area of a sphere are numerically equal then it's radius is

• A. $2units$
• B. $3units$
• C. $5units$
• D. $8units$

Answer 1

The correct option is B $3units$

Volume of sphere$=\frac{4}{3}\pi r^3$

Surface area of sphere$=4\pi r^2$

According to the question

$\Rightarrow \frac{4}{3}\pi r^3=4\pi r^2$

$\Rightarrow \frac{r}{3}=1$

$\Rightarrow r=3$