AMC12 2010 B

AMC12 2010 B · Q1

AMC12 2010 B · Q1. It mainly tests Percent, Arithmetic misc.

Makarla attended two meetings during her $9$-hour work day. The first meeting took $45$ minutes and the second meeting took twice as long. What percent of her work day was spent attending meetings?

Makayla 在她 $9$ 小时的工作日中参加了两个会议。第一个会议持续 $45$ 分钟，第二个会议持续时间是第一个的两倍。她工作日中用于参加会议的时间占百分之多少？

(A) 15 15

(B) 20 20

(D) 30 30

(E) 35 35

Answer

Correct choice: (C)

正确答案：（C）

Solution

The total number of minutes in her $9$-hour work day is $9 \times 60 = 540.$ The total amount of time spend in meetings in minutes is $45 + 45 \times 2 = 135.$ The answer is then $\frac{135}{540}$ $= \boxed{25\%}$ or $\boxed{(C)}$

她 $9$ 小时的工作日共有 $9 \times 60 = 540$ 分钟。参加会议的总时间（分钟）为 $45 + 45 \times 2 = 135$。因此所占比例为 $\frac{135}{540} = \boxed{25\%}$ 或 $\boxed{(C)}$。

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