Correct. Find the volume of each part and then add them together.

Volume of smaller pyramid: $\displaystyle{V}=\frac{{1}}{{3}}{l}{w}{h}=\frac{{1}}{{3}}{\left({8}\right)}{\left({8}\right)}{\left({6}\right)}=\frac{{1}}{{3}}{\left({384}\right)}={128}\usepackage{cmbright}\Huge\$

Volume of larger pyramid: $\displaystyle{V}=\frac{{1}}{{3}}{l}{w}{h}=\frac{{1}}{{3}}{\left({8}\right)}{\left({8}\right)}{\left({12}\right)}=\frac{{1}}{{3}}{\left({768}\right)}={256}\usepackage{cmbright}\Huge\$

Total volume: $\displaystyle{128}+{256}={384}\usepackage{cmbright}\Huge\$ cubic centimeters