A train 450 metre long takes 30 sec to cross a man running at a speed of 6 km/hr in the direction same to that of train. What is the speed of the train?
Let the speed of the train be x Relative speed = (x - 6) km/hr ⇒ (x - 6) = (450 × 18)/(30 × 5) ⇒ (x - 6) = (8100)/(150) ⇒ x – 6 = 54 ⇒ x = 54 + 6 = 60 km/hr