Chapter 4 - Proportions, Percents, and Solving Inequalities - 4.3 - More on Percents and Problem Solving - Problem Set 4.3 - Page 162: 39

The rate of the discount is 30%.

Let r represent the rate of the discount. A guideline for this problem would be: Original selling price - Discount = Discount sale price So, 180 - r $\times$ 180 = 126 180 - 180r = 126 180 - 126 = 180r 54 = 180r Divide both sides by 180: 0.3 = r Multiply the result by 100% to convert it to a percentage. 0.3 $\times$ 100% = 30% The rate of discount is 30%.