How many ounces of a 60% salt solution must be added to 40 ounces of a 20 percent salt solution so that the resulting mixture is 40% salt?  Answers.
A) 16.67
B) 40
C) 50
D) 60.33
E) 70

Rationale: "let x = ounces of 60 % salt solution to be added . 2 * 40 + . 6 x = . 4 ( 40 + x ) x = 40 amswer b"
Answer: B