Two train 130 m and 170 m long are running in same direction on a parallel track at the speed of 74 km/hr and 38 km/hr respectively. How long the faster train will take to cross the slower train?

30 sec

To cross the train, total distance to be traveled = Sum of length of trains

Distance = 130 + 170 = 300 m

Relative speed in same direction = S₁ - S₂ = 74 - 38 = 36 km/hr = 36 × \(\frac{5}{18}\) m/sec

⇒ Time to cross the slower train = \(\frac{Distance}{Relative\;Speed}\)

                                               = \(\frac{300\;×\;18}{36\;×\;5}\)

                                               = 30 Sec.