2014 AMC 10A Problem 6

Below is the professionally curated solution for Problem 6 of the 2014 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2014 AMC 10A solutions, or check the answer key.

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Concepts:ratio and proportionrate

Difficulty rating: 870

6.

Suppose that aa cows give bb gallons of milk in cc days. At this rate, how many gallons of milk will dd cows give in ee days?

bdeac\dfrac{bde}{ac}

acbde\dfrac{ac}{bde}

abdec\dfrac{abde}{c}

bcdea\dfrac{bcde}{a}

abcde\dfrac{abc}{de}

Solution:

We have to multiply bb by da\dfrac{d}{a} to account for the new number of cows.

We then have to multiply by ec\dfrac{e}{c} to account for the new time that we have.

This gives us a final answer of bdaec=bdeac. b \cdot \dfrac{d}{a} \cdot \dfrac{e}{c} = \dfrac{bde}{ac}.

Thus, A is the correct answer.

Problem 6 in Other Years