2023 AMC 8 Problem 13

Below is the video solution and professionally curated solution for Problem 13 of the 2023 AMC 8, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2023 AMC 8 solutions, or check the answer key.

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Concepts:fractionratio and proportion

Difficulty rating: 1240

13.

Along the route of a bicycle race, 77 water stations are evenly spaced between the start and finish lines, as shown in the figure below. There are also 22 repair stations evenly spaced between the start and finish lines. The 33rd water station is located 22 miles after the 11st repair station. How long is the race in miles?

88

1616

2424

4848

9696

Video solution:
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Written solution:

The 33rd water station is located 38\frac{3}{8} of the way along the race (the water stations split the race up into 88 equal spaces).

The first repair station is located 13\frac{1}{3} of the way along the race. The distance between the two is 3813=124 \dfrac{3}{8} - \dfrac{1}{3} = \dfrac{1}{24} the length of the race. We know that this equals 2,2, which means the race is 242=4824 \cdot 2 = 48 miles long.

Thus, D is the correct answer.

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