A train crosses a platform 90 metres long in 60 seconds at a speed of 54" " km/h. Find the time the train will take to cross an electric pole.

Correct option is B

Given:
Length of the platform = 90 meters
Speed of the train = 54 km/h
Time to cross the platform = 60 seconds

Solution:

Convert speed from km/h to m/s:
Speed in m/s = $$54 ×\frac{5}{18} = 15 m/s$$ 

Total distance = Length of the train + Length of the platform
Distance = Speed × Time
Length of the train + 90 = 15 × 60 = 900
Length of the train = 900 - 90 = 810 meters

The time to cross an electric pole:
Time = $$\frac{Distance}{Speed}$$​

Time = $$\frac{810}{15}$$= 54 Second

Thus the correct answer (B)