x = original price, or 100%
we know then that it original costs "x", which is the 100%, however is discounted by 40%, so the discounted price is really then 100% - 40% = 60%, and we know that that 60% is $12.
if 60% of the original price is $12, what is "x", the 100%?
[tex]\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} x&100\\ 12&60 \end{array}\implies \cfrac{x}{12}=\cfrac{100}{60}\implies \cfrac{x}{12}=\cfrac{5}{3}\implies 3x=60 \\\\\\ x=\cfrac{60}{3}\implies x=20 ~\hfill \stackrel{\textit{amount of the discount}}{20-12\implies 8}\\ ~\hspace{34em}[/tex]
