Let the speed and length of the train be x m/s and y m respectively. If train crosses a stationary pole in 3 minutes, Speed of the train = Total distance/Total time ⇒ Speed of the train = y/(3 × 60) ⇒ Speed of the train = y/180 ---- (1) If train crosses 600 m long platform 5 minutes, ⇒ Speed of the train = (y + 600)/(5 × 60) ⇒ y/180 = (y + 600)/300 ⇒ 5y = 3y + 1800 ⇒ 2y = 1800 ⇒ y = 900 m From(1), ⇒ Speed of the train = 900/180 = 5 m/sec ⇒ Speed of the train = 5 × 18/5 = 18 km/h ∴ The length and the speed of the train are 900 m and 18 km/h respectively.