Answer
$\displaystyle{V=4\pi}\\$
Work Step by Step
$\displaystyle{V=\int_{1}^{3}(2\pi y)\left(\frac{1}{y}\right)\ dy}\\
\displaystyle{V=2\pi\int_{1}^{3}1\ dy}\\
\displaystyle{V=2\pi\left[y\right]_{1}^{3}}\\
\displaystyle{V=2\pi\left(\left(3\right)-(1)\right)}\\
\displaystyle{V=4\pi}\\$