A toy store sells small cars for $1 each and trucks for $2 each. Brad wants to buy at least 12 vehicles, but can spend no more than $20. This situation is modeled by the system:

$\displaystyle{x}+{y}\ge{12}\usepackage{cmbright}\Huge\$

$\displaystyle{x}+{2}{y}\le{20}\usepackage{cmbright}\Huge\$

Graph this system of inequalities. The maximum number of cars that Brad can buy is _____.