A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?

Given Data

• Time past a man = 20 s (distance covered = train length)
• Time past platform = 36 s (distance covered = train length + platform length)
• Speed of train = 54 km/hr

Step 1: Convert speed to m/s
Speed = 54 × (5/18) = 15 m/s

Step 2: Find train length using the man-crossing time
Train length = Speed × Time = 15 × 20 = 300 m

Step 3: Use platform-crossing time
Distance to cross platform = 15 × 36 = 540 m 540 = Train length + Platform length = 300 + Platform length Platform length = 540 − 300 = 240 m

Final Answer
The length of the platform is 240 m.