Question

Belk's is having a 20% off sale on pajama pants. If the sale price was 12.50, what was the original price of the pajama pants?

Answer 1

Say the original price is "x", and therefore is the 100% of the price, however Belk's is having a sale and the pants were 20% off, therefore 12.50 is really just 100% - 20% or 80% of the original price.

now, we know 12.50 is the 80%, and "x" is the 100%, what the dickens is "x" anyway?

$\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 12.50&80\\ x&100 \end{array}\implies \cfrac{12.50}{x}=\cfrac{80}{100}\implies \cfrac{12.50\cdot 100}{80}=x$