## Elementary Algebra

Let r represent the rate of the discount. A guideline for this problem would be: Original selling price - Discount = Discount sale price So, 40 - r $\times$ 40 = 32 40 - 40r = 32 40 - 32 = 40r 8 = 40r Divide both sides by 40: 0.2 = r Multiply the result by 100% to convert it to a percentage. 0.2 $\times$ 100% = 20% The rate of the discount is 20%.