check the picture below.
[tex]\bf \textit{volume of a cylinder}\\\\
V=\pi r^2 h~~
\begin{cases}
h=2r\\
V=64
\end{cases}\implies 64=\pi r^2(2r)\implies 64=3\pi r^3\implies \boxed{\cfrac{64}{3\pi }=r^3}\\\\
-------------------------------\\\\
\textit{volume of a sphere}\\\\
V=\cfrac{4\pi r^3}{3}\qquad \qquad \implies V=\cfrac{4\pi \left( \boxed{\frac{64}{3\pi }} \right)}{3}\implies V=\cfrac{256}{9}[/tex]
