Question

If the area of the base of a right circular cone is $51m^2$ and volume is $68m^3$, then its vertical height is:

• A. $3.5m$
• B. $4m$
• C. $4.5m$
• D. $5m$

Answer 1

The correct option is B $4m$

The area of the base of a right circular cone $A=51m^2$
Volume $V=68m^3$
Then, to find $h$,

$\frac{V}{A}=\frac{\frac{1}{3}\pi r^{2}h}{\pi r^2}=\frac{68}{51}$
$⟹h=\frac{3\times 68}{51}$
$⟹h=4m$
Hence, option $B$ is correct.