A train travels from City A to City B at 60 km/h and returns at 40 km/h. What is the average speed for the entire trip?
Q1. A train travels from City A to City B at 60 km/h and returns at 40 km/h. What is the average speed for the entire trip?
Answer: 48 km/h
Explanation: Average speed = Total distance / Total time. Let's say the distance is D. Total distance = 2D. Time from A to B = D/60, from B to A = D/40. Total time = D/60 + D/40 = (2D + 3D)/120 = 5D/120 = D/24. Average speed = 2D / (D/24) = 48 km/h.