Question

A train is running at a speed of 45 km/hr and a man is walking at a speed of 5 km/hr in the opposite direction. If the train crosses the man in 18 seconds, then its length is 

(a) 200 m 

(b) 220 m 

(c) 180 m 

(d) 250 m

Answer 1

(d) 250 m

Since the man is walking in the opposite direction of the moving train, 

Relative speed of the train = (45 + 5) km/hr

= \(\bigg(50\times\frac{5}{18}\bigg)\) m/sec = \(\frac{250}{18}\) m/sec

Length of the train = Relative speed x Time taken in crossing the man

= \(\bigg(\frac{250}{18}\times18\bigg)\) m = 250 m.