In order to calculate the gross margin, we can use the formula below:
[tex]gross=\frac{net-cost}{net}[/tex]
If the gross margin is 60% = 0.6 and the cost per item is $8, the income per item sold is:
[tex]\begin{gathered} 0.6=\frac{net-8}{net}\\ \\ net-8=0.6net\\ \\ 0.4net=8\\ \\ net=\frac{8}{0.4}=20 \end{gathered}[/tex]
Therefore the sticker price is $20 (correct option: D)
