Average speed is given by total distance traveled divided the total time taken.
Given that the distance from Mason's home to their son's college campus is 154 miles, then a round trip (to and fro) from their house to their son's college campus will be 2 * 154 = 308 miles and the journey took 5 and a half hours.
Therefore, the average speed is given by:
[tex]Average\, speed= \frac{308\, miles}{5.5\, hours} =56\, miles/hour[/tex]
