A 150 m long train overtakes a man walking in the same direction at 2 km/h and takes 10 seconds to pass him completely. What is the speed of the train (in km/h)?

Introduction / Context:When a train overtakes a person going in the same direction, the relevant speed is the relative speed (train minus pedestrian). The train covers its own length relative to the man in the given time.

Given Data / Assumptions:

• Train length L = 150 m.
• Man speed = 2 km/h.
• Overtaking time = 10 s.
• Straight track; constant speeds.

Concept / Approach:Relative speed v_rel = L / time. Convert v_rel to km/h. Then train speed v_train = v_rel + pedestrian speed (because both move in the same direction).

Step-by-Step Solution:v_rel = 150 / 10 = 15 m/s.15 m/s = 15 * 3.6 = 54 km/h.Train speed v_train = 54 + 2 = 56 km/h.

Verification / Alternative check:Convert 56 km/h to m/s → 15.556 m/s. Subtract 2 km/h (0.556 m/s) to get ~15 m/s relative; times 10 s ≈ 150 m.

Why Other Options Are Wrong:52 and 84 km/h arise from subtracting/adding incorrectly or mixing units. “Data inadequate” is wrong because all needed values are provided.

Common Pitfalls:Using train speed directly without subtracting the man's speed, or forgetting to convert between m/s and km/h properly.

Final Answer:56 km/h