SSC MTS 6 Aug 2019 Shift 2 Paper

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.