Problem: how many ounces of a 60 % salt solution must be added to 50 ounces of a 20 percent salt solution so that the resulting mixture is 50 % salt ?
Rationale: "let x = ounces of 60 % salt solution to be added . 2 * 50 + . 6 x = . 5 ( 50 + x ) x = 150 answer e"
annotated_formula: divide(subtract(multiply(divide(50, const_100), 50), multiply(divide(20, const_100), 50)), subtract(divide(50, const_100), divide(20, const_100)))