Question

Find the volume and surface area of a sphere of radius $4.2$ cm. $[\pi =\frac{22}{7}]$

• A. $380.46{\text{cm}}^3,221.76{\text{cm}}^2$
• B. $320.46{\text{cm}}^3,221.76{\text{cm}}^2$
• C. $310.46{\text{cm}}^3,221.76{\text{cm}}^2$
• D. $370.46{\text{cm}}^3,221.76{\text{cm}}^2$

Answer 1

The correct option is C $310.46{\text{cm}}^3,221.76{\text{cm}}^2$

Given, radius of sphere $=4.2$ cm

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

$=\frac{4}{3}\times \frac{22}{7}\times 4.2\times 4.2\times 4.2=310.46{\text{cm}}^3$
Surface area of a sphere of radius '$r$' $=4\pi r^2=4\times \frac{22}{7}\times 4.2\times 4.2=221.76{\text{cm}}^2$