2005 AMC 10A Problem 7

Below is the professionally curated solution for Problem 7 of the 2005 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2005 AMC 10A solutions, or check the answer key.

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Concepts:distance rate and timelinear equation

Difficulty rating: 1240

7.

Josh and Mike live 1313 miles apart. Yesterday Josh started to ride his bicycle toward Mike's house. A little later Mike started to ride his bicycle toward Josh's house. When they met, Josh had ridden for twice the length of time as Mike and at four-fifths of Mike's rate. How many miles had Mike ridden when they met?

44

55

66

77

88

Solution:

Let Mike ride mm miles. Josh rides 45\frac{4}{5} the rate for 22 times the time, so Josh's distance is 85m.\frac{8}{5}m. Together they cover 13,13, so m+85m=135m=13,m + \frac{8}{5}m = \frac{13}{5}m = 13, giving m=5.m = 5.

Thus, the correct answer is B.

Problem 7 in Other Years