Correct Answer - Option 2 : 67%
Given:
The speed of the train = 45 km/hr.
The length of the train = 140 meters.
Formula used:
Distance = Speed × Time
Concept used:
To convert km/hr. to m/s, multiply by 5/18.
Calculation:
Speed of train = 45 × (5/18)
⇒ 25/2 m/s
According to the question:
Length of platform = [18 × (25/2) – 140]
⇒ 225 – 140
⇒ 85 m
Length of tunnel = [32 × (25/2) – 140]
⇒ 400 – 140
⇒ 260 m
Now, Required percentage = [{(260 – 85)/260} × 100]
⇒ (175/260) × 100
⇒ 67.30%
⇒ 67% (approximately)
∴ The answer is 67%.