6) A marketing firm determined that , of 160 households surveyed, 80 used neither Brand A nor Brand B soap.60 used only Brand A soap and for every household that used both brands of soap, 3 used only brand B soap.how many of the 200 household surveyed used both brands of soap? Choose the correct choice from the following answers.
A) 15 B) 20 C) 30 D) 40 E) 5

Rationale: "80 = at least one of soap a or b both brands = x brand b = 3 x = > 60 + x + 3 x = 120 = > 4 x = 20 = > x = 5 answer - e"
Answer: E