A train passes a station platform in 42 seconds and a man standing on the platform in 26 seconds. If the speed of the train is 29 m/s, what is the length of the platform?

1. A

   456

2. B

   466

3. C

   476

4. D

   464

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Explanation

• The core principle is that the additional time the train takes to pass the platform compared to passing a man is the exact time it takes to cover the length of the platform.
• First, calculate this time difference: 42 seconds (for the platform) - 26 seconds (for the man) = 16 seconds.
• Next, use the fundamental formula: Distance = Speed × Time.
• The length of the platform is the train's speed multiplied by this time difference: 29 m/s × 16 s = 464 meters.

Why Other Options Were Wrong

• Option A: This value (456) would be obtained if the time difference was miscalculated as approximately 15.72 seconds (456 ÷ 29), which is incorrect.
• Option B: This value (466) is a close but incorrect calculation. It may result from a minor error in multiplication (e.g., 29 x 16.07).
• Option C: This value (476) would be obtained if the time difference was miscalculated as approximately 16.41 seconds (476 ÷ 29), which is incorrect.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Calculating distance based on speed and time in problems involving trains and platforms as background academic context rather than a clinical decision trigger.
• While not a clinical question, quantitative reasoning is a critical skill for nurses.
• Nurses use similar calculations daily for drug dosages, IV drip rates, and fluid balance monitoring, where precision is vital for patient safety.
• What if? If the train's speed was 30 m/s instead of 29 m/s, the platform length would be 30 m/s × 16 s = 480 meters. This shows how a small change in a variable can significantly alter the outcome, similar to medication calculations.

How to Approach the Question

• First, identify all the given information: the train's speed (29 m/s), the time to pass a man (26 s), and the time to pass a platform (42 s).
• Recognize the key concept: The distance covered when passing a man is the train's length. The distance covered when passing a platform is the train's length PLUS the platform's length.
• The most efficient approach is to find the difference in time. This time difference (42s - 26s = 16s) is the time taken to cover the platform's length alone.
• Apply the formula Distance = Speed × Time to these specific values.
• Calculate the platform's length: 29 m/s × 16 s.
• Compare the result with the given options to find the correct answer.

Concept Tested & Keywords

• Concept Tested: Calculating distance based on speed and time in problems involving trains and platforms.
• Stem keywords: train, station platform, 42 seconds, man standing, 26 seconds, speed, 29 m/s, length of the platform
• Lead-in keywords: what is

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QoAFBu7Egh9KquAi6acEg5

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