A company sells trinkets in two different packages. A small box contains 3 trinkets for $2 and a large box contains 5 trinkets for $3. A customer bought more than 30 trinkets and spent more than $18. If $\displaystyle{s}\usepackage{cmbright}\Huge\$ represents the number of small boxes in the order and $\displaystyle{L}\usepackage{cmbright}\Huge\$ represents the number of large boxes, write a system of inequalitites to model the situation and graph it.