Correct. Find and add the volumes of the cylinder and the hemisphere.

Volume of cylinder: $\displaystyle\pi{{r}}^{{2}}{h}=\pi{{\left({20}\right)}}^{{2}}{\left({50}\right)}=\pi{\left({400}\right)}{\left({50}\right)}\approx{3.14}\cdot{20},{000}={62},{800}\usepackage{cmbright}\Huge\$

Volume of hemisphere: $\displaystyle\frac{{1}}{{2}}\cdot\frac{{4}}{{3}}\pi{{r}}^{{3}}=\frac{{2}}{{3}}\pi{{\left({20}\right)}}^{{3}}=\frac{{2}}{{3}}\pi\cdot{8},{000}\approx\frac{{2}}{{3}}\cdot{3.14}\cdot{8},{000}\approx{16},{747}\usepackage{cmbright}\Huge\$

Add the volumes together to find the volume of the silo: $\displaystyle{62},{800}+{16},{747}={79},{547}\approx{80},{000}\usepackage{cmbright}\Huge\$ cubic feet