2015 AMC 10A Problem 8
Below is the professionally curated solution for Problem 8 of the 2015 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2015 AMC 10A solutions, or check the answer key.
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Difficulty rating: 1280
8.
Two years ago Pete was three times as old as his cousin Claire. Two years before that, Pete was four times as old as Claire. In how many years will the ratio of their ages be : ?
Solution:
Let and be Pete's and Claire's current ages respectively.
Then we have that and Simplifying both equations gives us and Setting them equal, we have
This means that
Now, we need to find the number of years () until which gives us Thus, B is the correct answer.
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