(A) 55.58 m
(B) 81 m
(C) 61.3 m
(D) 87 m
Correct Option is: A
Given that,
The speed of the train = 25km/hr
= 25x 5/18 m/sec
= 125/18 m/sec
The train crosses a scooter in 12 seconds. Then,
Length of the train = 125/18*12= 83.33
Now, let the length of the platform is X m.
the train crosses the platform in 20 seconds.
Then, (X +83.3)/20 = 125/18
18(X +83.3)= 2500
18X=1000.6
X=55.58 m
Hence the platform is 55.58 m long.