2009 AMC 10A Problem 7

Attempt Problem 7 of the 2009 AMC 10A below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2009 AMC 10A solutions, or check the answer key.

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A carton contains milk that is

2\%

fat, an amount that is

40\%

less fat than the amount contained in a carton of whole milk. What is the percentage of fat in whole milk?

\dfrac{12}{5}

3

\dfrac{10}{3}

38

42

40\%

less than

x

means

60\%

x

Solve

0.6x = 2

Let whole milk be

x\%

fat. Since

2

40\%

less than

x,

we have

0.6x = 2,

x = \dfrac{2}{0.6} = \dfrac{10}{3}.

Thus, the correct answer is C.

Problem 7 in other years