A farmer has an apple orchard consisting of Fuji and Gala apple trees. Due to high winds this year 10% of his trees cross pollinated. The number of his trees that are pure Fuji plus the cross-pollinated ones totals 136, while 3/4 of all his trees are pure Fuji. How many of his trees are pure Gala? Choose the most appropriate option.
A) 24  B) 33  C) 55  D) 77  E) 88

Rationale: let f = pure fuji , g = pure gala and c - cross pollinated . c = 10 % of x where x is total trees . c = . 1 x also 3 x / 4 = f and c + f = 136 = > . 1 x + 3 / 4 x = 136 = > x = 160 160 - 136 = pure gala = 24 . a
Answer: A