GMAT Math

A research study determined that, of 350 households surveyed,
115 used neither Brand A or Brand B toothpaste, 85 used only
Brand A toothpaste, and for every 3 households that used only
Brand B toothpaste, 2 households used both brands of
toothpaste. How many of the 350 households surveyed used
only Brand B toothpaste?
(A 50
(B) 60
(C) 75
(D) 90
(E) 100

T = G1 + G2 - B + N
350 = 85 + 3x - 2x + 115
Answer wrong ?

let 3x use only B. then 2x use both.
thus only A + only B + Both + None = 350 -> 85+3x+2x+115 = 350 -> x=30 or 3x=90
IMO D