2010 AMC 12B Problem 1

Below is the professionally curated solution for Problem 1 of the 2010 AMC 12B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2010 AMC 12B solutions, or check the answer key.

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Concepts:percentageunit conversion

Difficulty rating: 800

1.

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

Solution:

The two meetings lasted 45+90=13545+90=135 minutes, and the work day is 960=5409\cdot60=540 minutes.

The fraction of the day spent in meetings is 135540=14=25%. \frac{135}{540}=\frac14=25\%.

Thus, the correct answer is C.

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