2006 AMC 10A Problem 3

Problem 3 of 25EasierAlgebra

The ratio of Mary’s age to Alice’s age is

3 : 5.

Alice is

30

years old. How many years old is Mary?

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Solution

Since the ratio is

3 : 5

and Alice is

30,

Mary is

\dfrac{3}{5} \cdot 30 = 18

years old. Thus, the correct answer is B.

Concepts: ratio and proportion · ages

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