David works at a resort from the beginning of March to the end of September. During the month of August this past year, he made 4 times the average (arithmetic mean) of his monthly totals in tips for the other months. His total tips for August were what fraction of his total tips for all of the months he worked? Answers:	A) 3 / 5	B) 2 / 5	C) 4 / 5	D) 1 / 5	E) 6 / 5

Rationale: first notice the number of months for which he worked - march to sept i . e . 7 months avg of monthly totals in tips for months other than august = x tips in august = 4 x total tips for all months = 6 * x + 4 x = 10 x tips for august / total tips for all months = 4 x / 10 x = 2 / 5 answer : b
Answer: B