Problem: a person travels from p to q a speed of 60 km / hr and returns by increasing his speed by 20 % . what is his average speed for both the trips ?
Rationale: "speed on return trip = 120 % of 60 = 72 km / hr . average speed of trip = 60 + 72 / 2 = 132 / 2 = 66 km / hr answer : d"
annotated_formula: divide(add(multiply(60, add(const_1, divide(20, const_100))), 60), const_2)