A train 550 metres long is running at a speed of 78 km/h. How many seconds will it take to cross a 350 metres long train running in the opposite direction at a speed of 30 km/h?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 30 seconds.
Speed of the first train = 78 km/h = 78 × (5/18) m/s = (65/3) m/s
Speed of the second train = 30 km/h = 30 × (5/18) = (25/3) m/s
Relative Speed = (65/3) + (25/3) = 30 m/s
Total Distance = 550 + 350 = 900 m
Time taken to cross = 900/30 = 30 seconds