how many ounces of a 60 % salt solution must be added to 30 ounces of a 20 percent salt solution so that the resulting mixture is 40 % salt ?
"let x = ounces of 60 % salt solution to be added . 2 * 30 + . 6 x = . 4 ( 30 + x ) x = 30 answer b"
divide(subtract(multiply(divide(40, const_100), 30), multiply(divide(20, const_100), 30)), subtract(divide(40, const_100), divide(20, const_100)))