Correct Answer - Option 4 : 18 sec
Given:
Speed of train = 54 km/h
Time train takes to cross a tree = 13 sec
Length of a platform = 75 m
Formula used:
Speed = Distance/Time
Calculation:
Speed of the train in m/sec = 54 × (5/18) = 15 m/sec
⇒ Length of the train = 15 × 13 = 195 m
Time taken to cross the platform = (195 + 75)/15
⇒ Time taken to cross the platform = 270/15 = 18 sec
∴ The time train will take to cross the platform is 18 sec.
