Question

Jeans are marked up 150% at Antoinette's Boutique. Today they are all on sale, 20% off the usual retail. If the wholesale price of jeans is $20, how much do they sell for today?

Answer 1

To solve the exercise you can use a rule of three.

Let us first find the usual price of jeans:

`\begin{gathered} \text{ \$20}\rightarrow100\text{\%}\Rightarrow\text{ wholesale price of jeans} \\ \text{ \$x}\rightarrow150\text{\%}\Rightarrow\text{ usual sale price of jeans} \end{gathered}`
`\begin{gathered} x=\frac{150\text{\%}\cdot\text{ \$20}}{100\text{ \%}} \\ x=\frac{150\cdot\text{\$20}}{100} \\ x=\text{\$}\frac{150\cdot\text{20}}{100} \\ x=\text{\$}(3000)/(100) \\ x=\text{\$}30 \end{gathered}`

Then, the usual price of the jeans is $30.

Now, let us find the discounted price of the jeans

`\begin{gathered} \text{ \$30}\rightarrow100\text{\%} \\ \text{ \$x}\rightarrow80\text{\%} \\ \text{ Because now the jeans have a 20\% discount, that is} \\ 100\text{\%}-20\text{\%}=80\text{\%} \end{gathered}`
`\begin{gathered} x=\frac{80\text{\%}\cdot\text{ \$30}}{100\text{ \%}} \\ x=\frac{80\cdot\text{ \$30}}{100} \\ x=\text{ \$}\frac{80\cdot\text{30}}{100} \\ x=\text{ \$}\frac{240\text{0}}{100} \\ x=\text{\$}24 \end{gathered}`

Therefore, today the jeans sell for $24.