Correct. Setting up the following system:

$\displaystyle{e}={10}\cdot{t}\usepackage{cmbright}\Huge\$

$\displaystyle{310}-{e}={8}\cdot{\left({34}-{t}\right)}\usepackage{cmbright}\Huge\$

you find that Adam worked for 19 hours, and Burt worked for 15 hours.