Question

9. A pair of jeans costs $30.64. That price includes tax which is

7.5%. What was the original price of the jeans?

Answer 1

well, the regular price before tax is "x", which oddly enough is the 100%, now let's add the 7.5% to that hmmmm that'd be 100% + 7.5% = 107.5%, and we know that 107.5% was $30.64, so hmmm

`\begin{array}{ccll} amount&\%\\ \cline{1-2} x & 100\\ 30.64& 107.5 \end{array} \implies \cfrac{x}{30.64}~~=~~\cfrac{100}{107.5} \\\\\\ 107.5x=3064\implies x=\cfrac{3064}{107.5}\implies x\approx 28.5`