Respuesta :

By definition we have to:
 v = d / t
 Where,
 v: speed
 d: distance
 t: time
 The time in hours is given by:
 t = 4 + (45/60)
 t = 4.75 hours
 Substituting values we have: 
 v = 456 / 4.75
 v = 96 km / h
 Answer:
 the speed of the train is:
 v = 96 km / h