数学两人赛跑问题：

假如有两个人赛跑，全长25米，A在B前面10米，A的速度是每秒5米，B的速度是A的两倍。

这样，因为A在B的前面，B要超过他就要路过A之前的位置，当B到10米的时候，A到了15米。等B到15米时候17.5米。因为B到A需要时间。这时间A又到B前面去了。所以永远追不上。

可是。用数学方法。A:25-10=5t A用3秒。B:25=10t B只用2.5秒。能追上。

-Mathematical two race question: if two people racing 25 meters in length, A B the first 10 m A speed of 5 meters per second, the speed of B is twice that of A' s. In this way, because the A in front of the B, B over he will come by the position, before the A and B to 10 meters, A to 15 meters. B to 15 m, 17.5 m. B to A takes time. This time A to B in front. So it can never catch up. But. Using mathematical methods. A :25-10 = 5t A 3 seconds. B: 25 = 10t B only 2.5 seconds. Able to catch up.