Question

This right circular cone has a volume of 75π cubic inches. The height of the cone is 9 inches. What is the length of the radius?

A) 4 in
B) 5 in
C) 6 in
D) 8 in

Answer 1

B) 5

Explanation:

Answer 2

`\bf \textit{volume of a cone}\\\\ V=\cfrac{\pi r^2 h}{3}\quad \begin{cases} r=radius\\ h=height\\ -----\\ V=75\pi \\ h=9 \end{cases}\implies 75\pi =\cfrac{\pi r^2\cdot 9}{3}\implies 75\pi =3\pi r^2 \\\\\\ \cfrac{75\pi }{3\pi }=r^2\implies 25=r^2\implies √(25)=r\implies 5=r`