Their average speed during the trip is 53 km/ hr approximately
Explanation: The family traveled 80 km/hr for an hour and then trabeled 40 km/ hr for 2 hours. So they traveled 80 km in one hour then 80 km in the next 2 hours. Total they traveled 160 km in 3 hours.
Average speed = distance traveled/ taken time
= 160/3 = 53.33
