作者anita7742 (歆小喵)
看板GMAT
标题[计量] GWD-13-35
时间Thu Jul 23 23:11:31 2009
Stations X and Y are connected by two separate, straight, parallel rail lines
that are 250 miles long. Train P and train Q simultaneously left Station X
and Station Y, respectively, and each train traveled to the other’s point of
departure. The two trains passed each other after traveling for 2 hours. When
the two trains passed, which train was nearer to its destination?
(1)At the time when the two trains passed, train P had averaged a speed of 70
miles per hour.
(2)Train Q averaged a speed of 55 miles per hour for the entire trip.
ans:原为C,但是在伤咖里的讨论串有人说是a？
讨论串中说A理由充分的原因是因为选项说"在交会时的平均速率为70",
所以代表p已经走了140miles了
可是我的疑问是：在交会时的平均速率＝前两小时的平均速率吗？
如果是在交会前两秒加速的怎麽办？
（完了我觉得这好像跟我的理化程度有关）
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1F：推 Calla:我觉得是A吧 翻交会时的平均速率不太准确 应该说"两台火车 07/25 00:40
2F：→ Calla:交会时 火车P的平均速率是一小时70 mi" 平均速率应该是指从 07/25 00:41
3F：→ Calla:发车交会时的平均速度 即使是交会前两秒加速到150 题目既给 07/25 00:41
4F：→ Calla:定交会时平均速率是70 可见他之前可能速度都低於70 应该是 07/25 00:42
5F：→ Calla:这样吧?! :D 07/25 00:42