Answer
$V=\pi r^2(\frac{100-2\pi r^2}{2\pi r +\pi}-2)$
Work Step by Step
Let $r$ be the inner radius and $h$ be the height
The volume of the tank is $V=\pi r^2(h-2)$
From part a, we found $h=\frac{100-2\pi r^2}{2\pi r +\pi}$
Thus, we have $V=\pi r^2(\frac{100-2\pi r^2}{2\pi r +\pi}-2)$
