2010 AMC 10B Problem 2

Attempt Problem 2 of the 2010 AMC 10B 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 2010 AMC 10B solutions, or check the answer key.

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2.

Makayla attended two meetings during her 99-hour work day. The first meeting took 4545 minutes and the second meeting took twice as long. What percent of her work day was spent attending meetings?

1515

2020

2525

3030

3535

Answer: C
Concepts:percentageunit conversion
Difficulty rating: 870
Solution:

Note that 4545 minutes is 4560=34 \dfrac{45}{60} = \dfrac{3}{4} hours. The second meeting is then 234=32 2 \cdot \dfrac{3}{4} = \dfrac{3}{2} hours. Both meetings take a total of 34+32=94 \dfrac{3}{4} + \dfrac{3}{2} = \dfrac{9}{4} hours then. The percent of Makayla's work day spent attending meetings is 100%949=100%14=25%. 100 \% \cdot \dfrac{\frac{9}{4}}{9} = 100 \% \cdot \dfrac{1}{4} = 25 \%.

Thus, C is the correct answer.

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