A train passes a station platform in 57 seconds and a man standing on the platform in 41 seconds. If the speed of the train is $29\mathrm{m/s}$, what is the length of the platform? (meter)

1. A

   464

2. B

   474

3. C

   484

4. D

   494

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

• The core principle is that the time to pass a stationary point object (a man) relates to the train's own length, while the time to pass a platform relates to the train's length plus the platform's length.
• The most efficient way to solve this is by finding the difference in time taken for both events.
• The extra time taken to pass the platform compared to the man is the precise time required for the train to travel the length of the platform.
• Time difference = 57 seconds (platform) - 41 seconds (man) = 16 seconds.
• Multiplying this time difference by the train's speed gives the platform's length: 29 m/s × 16 s = 464 meters.

Why Other Options Were Wrong

• Option B: This value is the result of an incorrect calculation. It does not correspond to any logical step derived from the problem's data.
• Option C: This value is the result of an incorrect calculation. It does not correspond to any logical step derived from the problem's data.
• Option D: This value is the result of an incorrect calculation. It does not correspond to any logical step derived from the problem's data.

Related Visual

• Visual 1: Diagram illustrating a train passing a man. The distance covered is shown to be equal to the length of the train.
• Visual 2: Diagram illustrating a train passing a platform. The total distance covered is shown as the sum of the train's length and the platform's length.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Application of Speed, Distance, and Time formulas in problems involving trains and platforms as background academic context rather than a clinical decision trigger.
• This question tests mathematical aptitude and logical reasoning, foundational skills for nurses who must perform accurate dosage calculations and interpret quantitative data.
• While the context is non-clinical, the underlying skill of applying a formula (Distance = Speed x Time) to a real-world problem is directly transferable to nursing practice (e.g., calculating IV drip rates).
• What if? If the man were walking on the platform in the same direction as the train, you would need to use the concept of relative speed. The effective speed to pass him would be (Speed of Train - Speed of Man).

How to Approach the Question

• Step 1: Identify the given information: Speed of the train (29 m/s), time to pass a platform (57 s), and time to pass a man (41 s).
• Step 2: Recognize that the 'man' is a point object and the 'platform' is a length object.
• Step 3: Understand that the difference in time between passing the platform and the man is the time it takes for the train to cover the length of the platform.
• Step 4: Calculate this time difference: 57 s - 41 s = 16 s.
• Step 5: Apply the fundamental formula: Distance = Speed × Time.
• Step 6: Calculate the platform's length by multiplying the train's speed by the time difference: 29 m/s × 16 s = 464 m.

Concept Tested & Keywords

• Concept Tested: Application of Speed, Distance, and Time formulas in problems involving trains and platforms.
• Stem keywords: train, station platform, man standing, speed, length of the platform
• Lead-in keywords: what is the length

Question ID

Q7CdO7VjDFVli1fNpT6u-t

Copy ID