Problem: a boy goes to his school from his house at a speed of 3 km / hr and returns at a speed of 2 km / hr . if he takes 5 hours in going and coming . the distance between his house and school is :
Rationale: "sol . average speed = [ 2 * 3 * 2 / 3 + 2 ] km / hr = 12 / 5 km / hr . distance travelled = [ 12 / 5 * 5 ] km = 12 km . ∴ distance between house and school = [ 12 / 2 ] km = 6 km . answer c"
annotated_formula: multiply(divide(5, add(divide(3, 2), const_1)), 3)