You may just have multiplied 2 and 20 and subtracted 32 from it or misplaced a decimal point. If T is the total before tax, n is the number of items, and p is the price of one item, then $\displaystyle{T}={k}{n}{p}\usepackage{cmbright}\Huge\$ . Substitute the given numbers, $\displaystyle{T}={32}\usepackage{cmbright}\Huge\$ , $\displaystyle{n}={20}\usepackage{cmbright}\Huge\$ , and $\displaystyle{p}={2}\usepackage{cmbright}\Huge\$ , and solve for k.