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.