A train 110 m long travels at 60 km/h. In how many seconds will it completely pass a 240 m long platform?

Introduction / Context:
Total distance to clear a platform equals train length + platform length. Convert speed to m/s and divide total distance by that speed to get time in seconds.

Given Data / Assumptions:

• L_train = 110 m; L_platform = 240 m.
• v = 60 km/h = 16.6667 m/s.

Concept / Approach:
S = 110 + 240 = 350 m. Time t = S / v_mps.

Step-by-Step Solution:

Verification / Alternative check:
Dimensional check yields seconds; magnitude aligns with typical moderate-speed trains.

Why Other Options Are Wrong:
18, 20, 24, 16 s do not match S/v with correct conversion.

Common Pitfalls:
Forgetting to add both lengths; mishandling 60 km/h to m/s conversion.

Final Answer:
21 sec