LENGTH of two trains are 200 m and 150 m respectively.SPEED of two trains are 45 km/hr and 40 km/hr respectively.If both train running in the same direction, then relative speed = 45 – 40 = 5 km/hr⇒ 5 km/hr = 5 × (5/18) = 25/18 m/secAs we know,Speed = distance/time⇒ 25/18 = (200 + 150)/TimeTime = 350/(25/18)Time = 14 × 18 = 252 seconds