Practice!

Sample Problem

A merchant put his $16 books on sale for $10,

 (a) By what percent did he decrease the selling price?

%

 (b) If he later raised the price of the books from $10 back to $16, by what percent did he increase the price?

%

Solution

(a) The original price is $16.

Percent Decrease= (amount of decrease)/original amount × 100%

Then, the Percent Decrease: (16 – 10) ÷ 16 = 0.375 = 37.5%

(b) The original price is $10.

Percent Increase= (amount of increase)/original amount × 100%

Then, the Percent Increase: (16 – 10) ÷ 10 = 0.6 = 60%