Problem: a train 150 m long passes a km stone in 15 seconds and another train of the same length travelling in opposite direction in 8 seconds . the speed of the second train is
Rationale: given that two trains are of same length i . e . . 150 mtrs first train passes the km stone in 15 seconds . here we have time and distance so speed = 150 / 15 = 10 m / s we need to find out the second train speed . suppose the speed of the 2 nd train is x m / s relative speed of two trains is ( 10 + x ) = = > ( 150 + 150 ) / ( 10 + x ) = 8 = = > ( 300 ) / ( 10 + x ) = 8 = = > 300 = 80 + 8 x = = > 300 - 80 = 8 x = = > 220 = 8 x : - x = 55 / 2 m / s convert m / s into km / ph ( 55 / 2 ) * ( 18 / 5 ) = 99 kmph answer : d
annotated_formula: multiply(divide(subtract(add(150, 150), multiply(divide(150, 15), 8)), 8), const_3_6)