Question

What is the volume of a cylinder that is 81.7% full, has a diameter of 16.4 inches and a height of 3 feet.

Answer 1

$\bf \textit{volume of a cylinder}\\\\ V=\pi r^2 h~~ \begin{cases} r=radius\\ h=height\\ ------\\ r=8.2\\ h=3 \end{cases}\implies V=\pi 8.2^2(3)\implies V=201.72\pi$

whatever% of anything is just (whatever/100) * anything.

thus, 81.7% of V is just (81.7/100) * V.