# Two trains, 80 metres and 120 metres long, are running at the speed of 25 km/hr and 35 km/hr respectively in the same direction on parallel tracks. How many seconds will they takes to pass each other ?

 [ A ]    48 [ B ]    64 [ C ]    70 [ D ]    72
 Answer : Option D Explanation : ATQ, Distance to be covered = 80+ 120 = 200m Relative speed = (35 â€“ 25) Ã—$5\over18$ = $25\over9$m/s So, time required to cross each other = 200 Ã— $29\over25$= 72 seconds