Two trains having lengths of 410 m and 390 m are running at speeds of 80 km/h and 100 km/h, respectively, in the same direction. The time taken (in minutes) by the faster train, coming from behind, to completely cross the other train is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 2.4
Relative speed = 100 km/h − 80 km/h = 20 km/h
Convert to m/s: 20 × 1000 / 3600 = 5.56 m/s
Total distance to cross = 410 m + 390 m = 800 m
Time = 800 / 5.56 ≈ 144 seconds = 2.4 minutes