AMC10 2015 B

AMC10 2015 B · Q2

AMC10 2015 B · Q2. It mainly tests Averages (mean), Arithmetic misc.

Marie does three equally time-consuming tasks in a row without taking breaks. She begins the first task at 1:00 PM and finishes the second task at 2:40 PM. When does she finish the third task?

Marie 连续做了三个耗时相等的任务，没有休息。她在下午 1:00 开始第一个任务，并在下午 2:40 完成第二个任务。她何时完成第三个任务？

(A) 3:10 PM 下午3:10

(B) 3:30 PM 下午3:30

(D) 4:10 PM 下午4:10

(E) 4:30 PM 下午4:30

Answer

Correct choice: (B)

正确答案：（B）

Solution

The first two tasks together took 100 minutes—from 1:00 to 2:40. Therefore each task took 50 minutes. Marie began the third task at 2:40 and finished 50 minutes later, at 3:30 PM.

前两个任务总共用了 100 分钟——从 1:00 到 2:40。因此每个任务用了 50 分钟。Marie 在 2:40 开始第三个任务，50 分钟后，即下午 3:30 完成。

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