(2)，V B =480/8=60(km/h)，--" ed =(8-7.25)* V B = 45(km)，

——《V A = 45/(7.7-7.25)= 100(km/h)，BC = (7.7-6.5) * V A = 120(km)，

—— OA = 480- 120 = 360 (km), that is, 360km starts from the starting point;

(3) The equation of 3)OD is y=60x, and that of BC is y= 100x-290, (6.5

-"ü (100 x-290)-60 times ü = ü 40x-290 ü.

So it meets the requirements.