PSAT Math Multiple-Choice Question 563: Answer and Explanation

Question: 563

An electronic reader typically costs $100. However, the price is heavily discounted due to both a coupon and a sale that have the same percent off the regular price. If the price using both the coupon discount and the sale discount is $49, what is the percent off the regular price that the coupon and the sale each provide independently

• A. 25%
• B. 30%
• C. 35%
• D. 40%

Correct Answer: B

Explanation:

(B) Since both the coupon and the sale provide the same percent discount, you can set up an equation to determine what you must multiply $100 by in order to end up with a price of $49. Alternatively, you can simply multiply $100 by the same variable twice, which will let you determine the correct percentage:

If x equals 0.7, subtract 0.7 from 1 to find the percent discount:

1 - 0.7 = 0.3 = 30%

This means that a 30 percent discount has been applied to the original amount two times.