Given: Length of each trains = 125 m Speed of train 1 = 18 m/s Speed of train 2 = 22 m/s Concept Used: When 2 trains move in the opposite direction, the relative speed is the sum of their speeds. Formula Used: Speed = Distance/Time Calculations: Let the time after which 2 trains will cross each other be t secs. (18+22)=(125+125)/t ⇒t=250/40 ⇒t=25/4 secs ∴ The time in which 2 trains will cross each other is 25/4 secs.