2023 AMC 12A Problem 2

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

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Concepts:linear equationfraction

Difficulty rating: 1020

2.

The weight of 13\tfrac13 of a large pizza together with 3123\tfrac12 cups of orange slices is the same as the weight of 34\tfrac34 of a large pizza together with 12\tfrac12 cup of orange slices. A cup of orange slices weighs 14\tfrac14 of a pound. What is the weight, in pounds, of a large pizza?

1451\tfrac45

22

2252\tfrac25

33

3353\tfrac35

Solution:

Let the pizza weigh PP pounds. Then 3123\tfrac12 cups weigh 7214=78\tfrac72\cdot\tfrac14=\tfrac78 and 12\tfrac12 cup weighs 1214=18.\tfrac12\cdot\tfrac14=\tfrac18.

The equation is 13P+78=34P+18. \tfrac13 P+\tfrac78=\tfrac34 P+\tfrac18.

Subtracting gives 7818=(3413)P,\tfrac78-\tfrac18=\left(\tfrac34-\tfrac13\right)P, so 34=512P\tfrac34=\tfrac{5}{12}P and P=95=145.P=\dfrac{9}{5}=1\tfrac45.

Thus, the correct answer is A.

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