A train runs at 18 km/h and its length is 120 m. How many seconds will it take to cross a man standing on a platform?

Introduction / Context:Passing a stationary man requires the train to cover its own length. Convert speed to m/s and divide train length by that speed to get the time.

Given Data / Assumptions:

• L = 120 m.
• v = 18 km/h.

Concept / Approach:v_mps = 18 * 5/18 = 5 m/s. t = L / v_mps = 120 / 5 seconds.

Step-by-Step Solution:

Verification / Alternative check:Back conversion: 24 s at 5 m/s covers 120 m—the train length.

Why Other Options Are Wrong:12, 22, 36, 44 s misapply conversions or lengths.

Common Pitfalls:Adding platform length (not needed); forgetting to convert km/h to m/s.

Final Answer:24 s