2008 AMC 10A Problem 4

Below is the professionally curated solution for Problem 4 of the 2008 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2008 AMC 10A solutions, or check the answer key.

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Concepts:ratio and proportionrate

Difficulty rating: 1040

4.

Suppose that 23\dfrac{2}{3} of 1010 bananas are worth as much as 88 oranges. How many oranges are worth as much as 12\dfrac{1}{2} of 55 bananas?

22

52\dfrac{5}{2}

33

72\dfrac{7}{2}

44

Solution:

Since 23\dfrac{2}{3} of 1010 bananas is 203\dfrac{20}{3} bananas worth 88 oranges, one banana is worth 8÷203=658 \div \dfrac{20}{3} = \dfrac{6}{5} oranges.

Now 12\dfrac{1}{2} of 55 bananas is 52\dfrac{5}{2} bananas, worth 5265=3\dfrac{5}{2} \cdot \dfrac{6}{5} = 3 oranges.

Thus, the correct answer is C.

Problem 4 in Other Years