TT13-35

rock19840717

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.

                  

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

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

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

D. EACH statement ALONE is sufficient.

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

答案选A，我选B，差的挺远的，B不是说平均全程55吗，那开了2小时相遇应该都能知道了啊，难道这55他在途中是变的？A的意思就说前2小时的平均速度是70，这样路程就一定了？只能这样理解了。。。