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标题: 求大神解析这道OG上的数学题 [打印本页]

作者: Jessie小潘潘    时间: 2019-11-2 14:17
标题: 求大神解析这道OG上的数学题
Station X and Y are connected by two seperate, straight, parallel rail lines that are 250 miles long. Train P and Q simultaneously left station X and Y, respectively, and each train traveled to the other's point of departure. The two train passed each other after travelling 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 spped of 70 miles per hour
2. Train Q averaged a speed of 55 miles per hour for the entire trip

条件2为什么不成立

作者: 七七x    时间: 2019-11-3 20:10
条件2中所说是整个路程平均速度,不是相遇之前的速度。全程速度55,不代表一直都是55,相遇之前可能很快也可能很慢。




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