Correct Answer - Option 4 : 54 kmph
Given:
A train passes a 60 metres long platform in 20 seconds
Same train passes a man standing on the platform in 16 seconds.
Formula used:
Distance = speed × time
Calculation:
Let the length of train be ‘L’ metres
Speed of train = (L + 60)/20 m/s ….(i)
Also while crossing the man,
Speed of train = L/16 m/s ….(ii)
Equating (i) and (ii), we get
(L + 60)/20 = L/16
⇒ 16L + 960 = 20L
⇒ 4L = 960
⇒ L = 240m
Speed of train = 240/16 = 15m/s
Converting 15m/s into km/hr = 15 × 3600/1000 = 54 km/hr
∴ The speed of the train is 54 km/hr
