A 500 metres long train crosses a man walking in opposite direction in 5 seconds. Speed of train is 9 times of the speed of man. What is the speed (in km/hr) of train?
Show answer & explanation
Correct answer: B
Explanation
Let the man's speed = x m/s.
Train's speed = 9x m/s.
Relative speed = 9x + x = 10x m/s.
Relative speed = 500/5 = 100 m/s.
10x = 100
x = 10 m/s.
Train's speed = 9 × 10 = 90 m/s.
= 90 × 18/5 = 324 km/h.