Ram, standing on a railway platform, noticed that a train took 36 seconds to completely pass through the platform, which was 108 m long, and it took 12 seconds to pass him. Find the speed of the train.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 16.2 km/h.
Let the speed of the train be x m/sec, and the length of the train be L meters
Time to pass Ram = 12 sec
L = 12x....(1)
Time to pass the platform = 36 sec
L + 108 = 36x......(2)
Put the value of L from equation 1 into equation 2
⇒ 12x + 108 = 36x
⇒ 24x = 108
⇒ x = m/sec
⇒ × = = 16.2 km/hr