Two trains of equal length are running on parallel lines in the same direction at speeds of 90 km/h and 51 km/h. The faster train passes the slower train in 36 seconds. The length of each train is:

Given:

Speed of faster train = 90 km/h

Speed of slower train = 51 km/h

Time to cross = 36 seconds

Trains are of equal length and moving in the same direction

Formula used:

Relative Speed = (Speed₁ - Speed₂)

Distance = Relative Speed × Time

Length of each train = (Distance ÷ 2)

Calculation:

⇒ Relative Speed = 90 - 51 = 39 km/h

⇒ 39 km/h = 39 × (1000 ÷ 3600) = 10.83 m/s

⇒ Distance = 10.83 × 36 = 389.88 m

⇒ Length of each train = 389.88 ÷ 2 ≈ 194.94 m

∴ The length of each train is approximately 195 metres.