Two trains 70 m and 80 m long respectively, run at the rates of 68 km and 40 km an hour respectively, on parallel rails in opposite directions. How long do they take to pass each other?
Correct Answer: 5 seconds
Explanation:
Total distance = 70 + 80 = 150 m
Relative speed = 68 + 40 = 108 kmph = 108 x (5/18) = 30 m/s
So time taken = 150 / 30 = 5 seconds.
