Correct Answer - Option 2 : 2 hours 40 minutes
Given:
Length of train = 318 m
Length of Bridge = 882 m
Time = 90 seconds
Formula used:
Speed = Distance/Time
Time = Distance/Speed
Train crosses a platform,
The distance covered by the train = The length of the train + The length of the bridge
Concept used:
I hour = 60 minutes
To convert a speed from m/s to km/h, we multiply it by 18/5
Calculation:
According to the question:
Speed = (318 + 882)/90 = 1200/90 = 40/3 m/s
New Distance = 128 km
Speed = 40/3 × 18/5 = 48 km/hr.
Time = 128/48 = 16/6 = 8/3
Time = 8/3 × 60 = 160 minutes = 2 hours 40 minutes
∴ The time covered by train is 2 hours 40 minutes.
