A car travels 200 km from A to B at 40 kph, and returns from B to A along the same route at 60 kph. What is the average speed of the round trip?
From A to B, the distance is 200. The time taken is 200/40=5 hours. From B to A, the distance is also 200. The time taken is 200/60=10/3 hours. The average speed is total distance/total time.