Question

A train 180 m long crosses a platform 270 m long in 30 seconds. The speed of the train is

• A. 54 km/h
• B. 45 km/h
• C. 60 km/h
• D. 50 km/h

Hint:

Crossing distance is train length plus platform length; then convert m/s to km/h using 18/5.

Answer 1

The Correct Option is A

Step 1: Total distance to be covered while crossing the platform $=$ train length $+$ platform length $=180+270=450$ m $=0.45$ km.
Step 2: Time taken $=30$ seconds $=\dfrac{30}{3600}$ hours $=\dfrac{1}{120}$ hour.
Step 3: Speed (km/h) $=\dfrac{\text{distance (km)}}{\text{time (h)}}=0.45\div\dfrac{1}{120}=0.45\times120=54$ km/h.
\[\boxed{54\text{ km/h}}\]