Two trains, each 180 m long, are moving towards each other on parallel tracks at speeds of 50 km/hr and 70 km/hr. In how many seconds will they completely cross each other?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 10.8.
Length of each train = 180 m
Speeds = 50 km/hr and 70 km/hr
Convert speeds to m/s:
50 km/hr = (50 × 1000) / 3600 = 13.89 m/s
70 km/hr = (70 × 1000) / 3600 = 19.44 m/s
Relative speed = 13.89 + 19.44 = 33.33 m/s
Total length to cross = 180 + 180 = 360 m
Time = Distance / Speed = 360 / 33.33 = 10.8 seconds