Answer: (1) The speed of high-speed train is v 1=250km/h, and the speed of ordinary train is v2= 100km/h, so

V1:v2 = 250:100 = 5:2, and the ratio of high-speed trains to ordinary trains is 5: 2.

(2) It takes t 1=500÷250=2(h) for the high-speed rail to go from A to B.

The time for the ordinary train to travel from A to B is t2=500÷ 100=5(h).

So the time ratio between high-speed rail and ordinary express from A to B is 2:5.