According to the position vs time graph, the <em>average</em> <em>velocity</em> of the motorcycle is the change in position divided by the change in time. Also, note that the slope is linear and positive throughout the 5 hours, it doesn't change direction.
Therefore, we have Avg velocity = change in direction/change in time Avg velocity = (150km - 30km)/(5h - 0h) Avg velocity = 24km/hr south.