Correct Answer - Option 3 : 20
Given:
The speed of a man traveling on a bicycle is 5 m/sec.
The speed of the train coming from behind is 50 m/sec which crosses him in 10 seconds.
The length of the platform is 550 m.
Formula Used:
Relative Speed = Distance/Time
Calculation:
Let the length of the train be L.
⇒ L = (50 – 5) × 10
⇒ L = 450 m
As speed of the train is 50 m/sec, then the time(T) taken by the train to cross the platform of length 550 m will be
⇒ (450 + 550) = (50) × T
⇒ T = 1000/50 = 20 sec
∴ The time taken by the train to cross the platform is 20 seconds.