hmmm what is now discounted? well, let's assume it sells normally for 499 and is discounted today at 25%, how much is that?
well, if we take 499 to be the 100, how much is 25%?
[tex]\bf \begin{array}{ccll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
499&100\\
d&25
\end{array}\implies \cfrac{499}{d}=\cfrac{100}{25} \cfrac{499\cdot 25}{100}=d
\\\\\\
124.75=d\qquad \textit{so the new price is }499-124.75\implies 374.25[/tex]
now, applying the sales tax to the discounted price.
if we take 374.25 to be the 100%, how much is 6.5%?
[tex]\bf \begin{array}{ccll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
374.25&100\\ t&6.5
\end{array}\implies \cfrac{374.25}{t}=\cfrac{100}{6.5}\implies \cfrac{374.25\cdot 6.5}{100}=t[/tex]
so, the total cost will then be 374.25 + t.
