PSAT Math Multiple-Choice Question 66: Answer and Explanation

Question: 66

At a buffet restaurant, students pay $5 per meal and non-students pay $7. The total revenue, R, in dollars, earned per day by the restaurant is given by the equation R = 5s + 7n, where s is the number of student customers and n is the number of non-student customers. Which of the following represents the total number of customers on a given day?

• A. s - n
• B. s + n
• C. sn
• D.

Correct Answer: B

Explanation:

B

The question asks for an expression representing a certain piece of information in the context of an equation. Start by reading the full question, which asks for an expression that represents the total number of customers on a given day. Then label the parts of the equation with the information given. The question states that R is the total revenue earned by the restaurant in one day, s is the number of student customers, and n is the number of non-student customers. Focus on the information that is needed to answer the question. The total number of customers is equal to the number of student customers, s, and the number of non-student customers, n. Add these two groups together to get the overall total. The calculation for this is s + n. The correct answer is (B).