The volume of a sphere is 38808 cm3.

Question:

The volume of a sphere is 38808 cm3. Find its radius and hence its surface area.

Solution:

Volume of the sphere = 38808 cm3

Suppose that r cm is the radius of the given sphere.

$\therefore \frac{4}{3} \pi r^{3}=38808$

$\Rightarrow r^{3}=\frac{38808 \times 3 \times 7}{4 \times 22}=9261$

$\Rightarrow r=\sqrt[3]{9261}=21 \mathrm{~cm}$

$\therefore$ Surface area of the sphere $=4 \pi r^{2}$

$=4 \times \frac{22}{7} \times 21 \times 21$

$=5544 \mathrm{~cm}^{2}$

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