Relative speed (when moving towards each other) = Speed of train A+ Speed of train B Time taken to meet = Distance ∕ Relative speed Calculation: Relative speed =20+50=70km∕hr Distance covered by Train A from 9:00 A.M. to 10:00 A.M.: Distance = Speed × Time Distance =20×1=20km Remaining distance to cover = Total distance - Distance covered by Train A Remaining distance =370−20=350km Time taken to cover the remaining distance: Time = Distance ∕ Relative speed Time =350∕70 ⇒ Time =5 hours Meeting time = Start time of Train B + Time taken to meet Meeting time = 10:00 A.M. + 5 hours ⇒ Meeting time = 3:00 P.M .