Since all merchandise has 20% off, so the original price is multiplied by 0.8 (80%).
Let's use the variable x to represent the original price. So we can write the following equation and solve it for x:
[tex]\begin{gathered} 0.8\cdot x=13 \\ x=\frac{13}{0.8} \\ x=16.25 \end{gathered}[/tex]Therefore the original price is $16.25.
