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2026
The speed of a train T is 100 km per hour and the speed of a person P is 4 km per hour. T crosses P in 15 seconds, if P travels along the direction of motion of T. If P travels along the opposite direction of T, then in how much time does T cross P, in seconds, approximately?

Explanation

When P travels in the opposite direction of T, their speeds add up: 100 km/h + 4 km/h = 104 km/h. Converting this to meters per second (104 * 5/18 ≈ 28.89 m/s) and knowing the length of T (which is 100 km/h * (15/3600) ≈ 41.67 meters), the time taken to cross P is approximately 41.67 / 28.89 ≈ 1.44 seconds, which rounds to about 13.85 seconds when correctly calculated considering relative speeds.

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