A boy walks a total distance of 10 km. His starting position is at rest and his final position is 4 km. If it takes him 1 hour and 20 minutes to make this trip, what is his velocity?
10km/(1hr 20min) = 10km/(4/3 hr) = 7.5 km/hr
That is his speed. The velocity is unknown, since you did not specify a direction.
By the way, 7.5 km/hr is a pretty fast walking speed.