Two trains having lengths of 370 m and 330 m are running at speeds of 90 km/h and 150 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: D
Explanation
The correct answer is option 4 i.e. 0.7
Length of faster train = 330 m
Length of slower train = 370 m
Total distance to cross = 330 + 370 = 700 m
Speed of faster train = 150 km/h = 150 × (5 ÷ 18) = 41.6667 m/s
Speed of slower train = 90 km/h = 90 ×(5 ÷ 18) = 25 m/s
Relative speed = 41.6667 − 25 = 16.6667 m/s
Time to cross = 700 ÷ 16.6667 = 42 seconds
Convert to minutes = 42 ÷ 60 = 0.7 minutes