2006 AMC 12A Problem 3

Below is the professionally curated solution for Problem 3 of the 2006 AMC 12A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2006 AMC 12A solutions, or check the answer key.

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Concepts:ratio and proportionages

Difficulty rating: 800

3.

The ratio of Mary's age to Alice's age is 3:5.3 : 5. Alice is 3030 years old. How old is Mary?

1515

1818

2020

2424

5050

Solution:

Mary's age is 35\tfrac{3}{5} of Alice's, so Mary is 3530=18\tfrac{3}{5}\cdot 30 = 18 years old.

Thus, the correct answer is B.

Problem 3 in Other Years