Each month, after Jill pays for rent, utilities, food, and other necessary expenses, she has one fifth of her net monthly salary left as discretionary income. Of this discretionary income, she puts 30% into a vacation fund, 20% into savings, and spends 35% on eating out and socializing. This leaves her with $99 dollar, which she typically uses for gifts and charitable causes. What is Jill’s net monthly salary? Options:  A) $ 2400  B) $ 3300  C) $ 6000  D) $ 6400  E) $ 9600

Rationale: "let x be the monthly salary 15 % of 1 / 5 * x = 99 x = 3300 answer b"
Answer: B