A train 220 m long passes a person walking at 6 km/h in the same direction in 11 seconds. What is the speed of the train?

💡 Solution & Explanation

When both move the same way, the train passes the person at the difference of their speeds. That relative speed = 220 m ÷ 11 s = 20 m/s = 20 × 18/5 = 72 km/h. So the train's own speed = 72 + 6 = 78 km/h. Forgetting to add the walking speed gives 72 km/h.