A 240 m long train crosses a platform of equal length (240 m) in 27 seconds. What is the train’s speed in km/h?

Introduction / Context:
Total distance to cross equals the sum of train and platform lengths. With time in seconds, find m/s then convert to km/h.

Given Data / Assumptions:

• L_train = 240 m; L_platform = 240 m; total S = 480 m.
• t = 27 s.

Concept / Approach:
v_mps = S/t = 480/27 = 160/9 ≈ 17.7778 m/s; v_kmph = v_mps * 3.6 ≈ 64 km/h.

Step-by-Step Solution:

Verification / Alternative check:
Back convert: 64 km/h = 17.7778 m/s; over 27 s gives 480 m—correct.

Why Other Options Are Wrong:
48, 52, 56, 60 km/h correspond to arithmetic mean errors or rounding the time improperly.

Common Pitfalls:
Using only train length; mixing hours/minutes/seconds in conversion.

Final Answer:
64