AMC12 2015 B

AMC12 2015 B · Q2

AMC12 2015 B · Q2. It mainly tests Rates (speed).

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连续完成三项耗时相等的任务，没有休息。她在下午1:00开始第一项任务，并在下午2:40完成第二项任务。她何时完成第三项任务？

(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

Answer (B): 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.

答案（B）：前两个任务一共用了100分钟——从1:00到2:40。因此每个任务用了50分钟。玛丽在2:40开始第三个任务，并在50分钟后完成，即下午3:30。

Topics

AR.007 Rates (speed)