First lets cover our basic known information :
Average speed = (total distance covered) / (time to cover the distance)
Total distance covered = (88 km + 84 km) = 172 km
Time to cover the distance = (4 hr + 3 hr) = 7 hours
Average speed = (172 km) / (7 hours)
Solve and your answer should be ::
24.57 kilometers per hour
hope i helped, good luck!
