Correct. Let a, c, and s be the cost of one adult, child, and senior ticket. Then:

$\displaystyle{2}{a}+{3}{c}={28}\usepackage{cmbright}\Huge\$

$\displaystyle{a}+{c}+{2}{s}={22}\usepackage{cmbright}\Huge\$

$\displaystyle{s}={c}+{1}\usepackage{cmbright}\Huge\$ or $\displaystyle-{c}+{s}={1}\usepackage{cmbright}\Huge\$

Multiply the third equation by $\displaystyle-{2}\usepackage{cmbright}\Huge\$ and add it to the second: $\displaystyle{a}+{3}{c}={20}\usepackage{cmbright}\Huge\$

Multiply this by $\displaystyle-{1}\usepackage{cmbright}\Huge\$ and add it to the first equation: $\displaystyle{a}={8}\usepackage{cmbright}\Huge\$

Substitute into the first to find $\displaystyle{c}={4}\usepackage{cmbright}\Huge\$ , and then into the third to find $\displaystyle{s}={5}\usepackage{cmbright}\Huge\$ .