## Thinking Mathematically (6th Edition)

$\467.2$
Let dealer’s cost be $p$ and the selling price be $s$ $\therefore s=584$ And, Markup price \begin{align} & =p\times \frac{25}{100} \\ & =\frac{p}{4} \\ \end{align} Since markup is the amount added to the dealer’s cost of an item to arrive at the selling price of that item.So, we can write: Selling price $=$dealer’s cost +markup Putting corresponding values obtained, we get: \begin{align} & s=p+\frac{p}{4} \\ & =\frac{4p+p}{4} \\ & =\frac{5p}{4} \end{align} After cross multiplying, we get: $p=\frac{4s}{5}$ Now on putting here the given value of $s$,we get: \begin{align} & p=\frac{4\times 584}{5} \\ & =\frac{2336}{5} \\ & =467.2 \end{align} Hence dealer’s cost is $\467.2$