Sandy bought 65 books for $1280 from one shop and 55 books for $880 from another shop. What is the average price that Sandy paid per book?	Choose the correct choice from the following choices.
A) $ 12
B) $ 14
C) $ 16
D) $ 18
E) $ 20

Rationale: "average price per book = ( 1280 + 880 ) / ( 65 + 55 ) = 2160 / 120 = $ 18 the answer is d ."
Answer: D