the velocity of a train is 80.0km/h, due west. 1hr an 30min later, its velocity is 65.0km/h, due west. Whats the train average velocity

Answer 1

There is not enough information to solve this. You need for average velocity the distance the train went. There is no indication of what velocity was doing during the 1.5hr time period.

Answer 2

65-80/1.5= -10km/h^2 , due east