Question

The cost of a pair of ice skates went from $200 to $140. What is the percent change in the cost of skates?

Answer 1

so the pair went down from 200 to 140, so the difference is 200 - 140 = 60.

so if we take 200 as the 100%, what is 60 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 200&100\\ 60&x \end{array}\implies \cfrac{200}{60}=\cfrac{100}{x}\implies \cfrac{10}{3}=\cfrac{100}{x}\implies 10x=300 \\\\\\ x = \cfrac{300}{10}\implies x = 30$