# SAT Math Multiple Choice Question 841: Answer and Explanation

### Test Information

Question: 841

1. John buys c pounds of cheese to feed m people at a party. If m + n people come to the party, how many more pounds of cheese must John buy in order tofeed everyone at the original rate?

• A.
• B.
• C.
• D.

Explanation:

D

Difficulty: Hard

Category: Problem Solving and Data Analysis / Rates, Ratios, Proportions, and Percentages

Strategic Advice: This is a great question in which you can pick convenient numbers to represent the variables given and work through the answer choices using those numbers.

Getting to the Answer: Say John buys 10 pounds of cheese for 5 people (that is, c = 10 and m = 5). Then everyone gets 2 pounds of cheese. Also, say 8 people come, 3 more than expected (that is, n = 3). Then John needs 16 pounds to have enough for everybody to consume 2 pounds of cheese. Because he already bought 10 pounds, he must buy an additional 6 pounds. Therefore, an answer choice that equals 6 when you substitute 10 for c, 5 for m, and 3 for n is the correct choice:

Choice A:. Eliminate.

Choice B:. Eliminate.

Choice C:. Eliminate.

Choice (D):. Choice (D) is correct.