Q:

What is the value of the ratio of the surface area to the volume of the cylinder. A cylinder has a radius of 4 ft and a height of 12 ft.A. 0.39B. 0.82C. 1.5D. 0.67

Accepted Solution

A:
[tex]\bf \textit{total surface area of a cylinder}\\\\ SA=2\pi r(h+r)~~ \begin{cases} r=radius\\ h=height\\ -----\\ r=4\\ h=12 \end{cases}\implies SA=2\pi (4)(12+4) \\\\\\ SA=8\pi (16)\implies SA=128\pi \\\\ -------------------------------\\\\ \textit{volume of a cylinder}\\\\ V=\pi r^2 h~~ \begin{cases} r=radius\\ h=height\\ -----\\ r=4\\ h=12 \end{cases}\implies V=\pi (4)^2(12)\implies V=192\pi[/tex]

[tex]\bf -------------------------------\\\\ \cfrac{SA}{V}\qquad \qquad \cfrac{128\pi }{192\pi }\implies \stackrel{simplified}{\cfrac{2}{3}}[/tex]