Problem: how many seconds will a 500 m long train take to cros a man walking with a speed of 3 kmph in the direction of the moving train if the speed of the train is 63 kmph
Rationale: time = distance ( here length of the train ) / relative speed ( 63 - 3 ) thus time = 500 / 60 * 5 / 18 = 500 * 18 / 60 * 5 = 30 seconds answer : b
annotated_formula: divide(500, divide(subtract(63, 3), const_3_6))