PSAT Math Multiple-Choice Question 334: Answer and Explanation

Question: 334

If 3r + 2s = 24 and r + s = 12, what is the value of r + 6?

• A. 0
• B. 4
• C. 6
• D. 12

Correct Answer: C

Explanation:

C

Difficulty: Medium

Getting to the Answer: Since the question asks for r + 6, substitute by solving for s using the second equation, r + s = 12, so s = 12 - r. Substitute 12 - r into the first equation to get 3r + 2(12 - r) = 24. Distribute the 2 to get 3r + 24 - 2r = 24. Next, combine like terms: 3r - 2r = 24 - 24, which yields r = 0. Remember that the question asks for r + 6, not r by itself!

Choice (C) is correct.