40 km route: first 20 km at 10 km/h, next 20 km at 20 km/h. Average speed?
Q1. 40 km route: first 20 km at 10 km/h, next 20 km at 20 km/h. Average speed?
Answer: 13.3 km/h
Explanation: Total time 3 h for 40 km → 40/3 ≈ 13.3 km/h. Not the arithmetic mean of speeds.