Tips & Tricks Given The ratio of speed of two trains A and B = 3 : 4. Formula Time = Distance/Speed Calculation Let the speed of train A and B be 3x and 4x. Time taken by train A to cover 480 km - Time taken by train B to cover 480 km = 2 ⇒480/3x−480/4x=2 ⇒480/12x=2 ⇒40/x=2 ⇒x=20 ∴ Speed of train A = 3x = 3 × 20 = 60 km/h