a) In the first time period the distance traveled is greater than the time which means that the speed would be greater than 1 km/min, for the second time period they are equal which would mean that the speed is 1 km/min and for the third the speed would be greater than 1 km/min since the distance is greater than the time. The speed is greater than 1 km/min, equal to 1 km/min and again greater than 1km/min.
b) Using the fact that
, we can calculate each average rate
c) For the overall average speed we have a total distance
of 110 km in 90 minutes which gives
d) The overall average speed makes sense since the three partial speeds range from 1 km/min to 1.33 km/min, the overall average should fall within that range, which it does.