PSAT Math Multiple-Choice Question 326: Answer and Explanation

Question: 326

An Internet provider charges k dollars for the first hour of use in a month and m dollars per hour for every additional hour used that month. If Jared paid $65.50 for his Internet use in one month, which of the following expressions represents the number of hours he used the Internet that month?

• A.
• B.
• C.
• D.

Correct Answer: D

Explanation:

D

Difficulty: Hard

Category: Word Problems

Getting to the Answer: Let h be the number of hours Jared spent using the Internet during the month. The first hour costs k dollars and the remaining hours (h - 1) are charged at the rate of m dollars per hour. Therefore, the total charge for a month is k + (h - 1)m. Set this equal to the amount Jared paid and solve for h. Note that you're not going to get a numeric answer because the question doesn't give you the actual rates:

This expression matches (D). Note that you could also use Picking Numbers to answer this question.