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.


Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

EACH statement ALONE is sufficient.

Statements (1) and (2) TOGETHER are NOT sufficient.

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题目分析：

（1）    相遇时，P火车过去的平均时速为每小时70英里。所以，相遇时P火车行驶的距离为70*2=140英里，此时P距离终点为250-140=110英里。所以Q火车离终点距离为140英里，P火车离终点更近。题目得解。

（2）    仅根据条件2，不知道P的速度，也就无法计算火车相遇的时间，无法计算相遇时离终点的距离。不满足要求

因此，本题答案为（A），仅条件1可以解题，条件2不行。

 

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