Traditions Clothing Store is having a sale. Shirts that were regularly priced at $20 are on sale for $17. What is the percentage of decrease in the price of the shirts?
original price of shirts = $ 20
new price of shirts = $17
decrease in price = $20 - $17 = $ 3
% decrease = 3/20 x 100 = 15%
\(\begin{array}{ccc}\$20&-&100\%\\\\\$17&-&p\%\end{array}\\\\\\cross\ multiply\\\\20p=17\cdot100\ \ \ /:20\\\\p=\frac{1700}{20}\\\\p=85\ (\%)\\\\100\%-85\%=15\%\leftarrow Answer\)