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 40 % salt ?
"for 60 % salt solution ( x ) and 20 % salt solution ( y ) to give 40 % = ( 60 + 20 ) / 2 salt solution , we should mix equal amounts of x and y . answer : c ."
divide(subtract(multiply(divide(40, const_100), 50), multiply(divide(20, const_100), 50)), subtract(divide(40, const_100), divide(20, const_100)))