The time taken by a 180 m long train running at a speed of 54 km/h to cross a man standing on the platform is:

10 seconds 12 seconds 11 seconds 9 seconds

12 seconds

Speed of train = 54 km/h 54 km/h= 54 × \(\frac{5}{18}\)m/sec  =  15 m/sec Distance = Speed ×  Time 180 =15 × Time Time = 12 sec