What is the length of the platform? I. Train X running at the speed of 25 km/hr crosses a platform in 18 seconds. II. Train X crosses a man moving at the speed of 5 km/hr in the opposite direction in 12 seconds. III. Train X crosses a pole in 14.4 seconds.
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Any two
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I and either II or III
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Any one
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Only III
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Only II
B
Correct answer
Explanation
From I and II: Platform length = (25+5) × 5/18 × 12 = 100 m train length. Then from I: 100 + platform = 25 × 5/18 × 18 = 125, so platform = 25 m. From I and III: Train length = 25 × 5/18 × 14.4 = 100 m, same calculation. Either II or III gives train length when combined with I. III alone gives only train length (100 m), not platform. II alone is insufficient without train speed from context.