+46 If Bob drove 180 km from Toronto to London at 90 km/h, then drove back at only 60 km/h, what was his average speed over the entire trip?
+23252 Driving 180 km at 90 km/h would take 2 hours. (180 km / 90 km/h = 2 h.)
Driving 180 km at 60 km/h would take 3 hours. (180 km / 60 km/h = 3 h.)
The total distance of the trip is 180 km + 180 km = 360 km.
The total time is 2 h + 3 h = 5 h.
The average speed = 360 km / 5 h = 72 km/h.
