so let's say the sale price is "P", so Nicole would want to know how much will it be P discounted by 18% of P.
Well, the sale price will just be P or 100% of P, minus 18%, the discounted price will be 100% - 18% = 82%, so the discounted price will be 82% of P.
[tex]\begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{82\% of P}}{\left( \cfrac{82}{100} \right)P}\implies \boxed{0.82}\cdot P\qquad \impliedby \textit{discounted price}[/tex]
