Uncle Bruce is baking chocolate chip cookies. He has 36 ounces of dough (with no chocolate) and 13 ounces of chocolate. How many ounces of chocolate are left over if he uses all the dough but only wants the cookies to consist of 20% chocolate?	Choose the correct choice from the following choices
A) 4
B) 6
C) 7.2
D) 7.8
E) 9

Rationale: answer is a . x / x + 36 = 1 / 5 x = 9 13 - 9 = 4
Answer: A