Question

The volume of a cone is $462$ m${}^3$. Its base radius is $7$ m. Find its height.

• A. $6$
• B. $7$
• C. $8$
• D. $9$

Answer 1

Answer: (D)

$9$

Given volume of cone is $462$ cu. m and its base radius is $7$ m.

We know that volume $=$ $V=\frac{1}{3}\pi r^{2}h$

$\Rightarrow h=\frac{3\times V}{\pi r^2}$

$\therefore h=\frac{3\times 462}{\frac{22}{7}(7{)}^2}$

$\Rightarrow h=\frac{3\times 462}{22\times 7}=\frac{1386}{154}=9$ m.

Hence, option $D$ is correct.