2023 AMC 12B Problem 2

Below is the professionally curated solution for Problem 2 of the 2023 AMC 12B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2023 AMC 12B solutions, or check the answer key.

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Concepts:percentagework backwards

Difficulty rating: 1020

2.

Carlos went to a sports store to buy running shoes. Running shoes were on sale, with prices reduced by 20%20\% on every pair of shoes. Carlos also knew that he had to pay a 7.5%7.5\% sales tax on the discounted price. He had 4343 dollars. What is the original (before discount) price of the most expensive shoes he could afford to buy?

4646

5050

4848

4747

4949

Solution:

The final cost of a pair with original price pp is 0.8×1.075×p=0.86p.0.8\times 1.075\times p=0.86p. Setting 0.86p430.86p\le 43 gives p50,p\le 50, so the most expensive affordable pair originally cost 5050 dollars.

Thus, the correct answer is B.

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