Alfred buys an old scooter for $4700 and spends $800 on its repairs. If he sells the scooter for $6400, his gain percent is?	Choose one.
A) 5.45 % B) 16.36 % C) 7 % D) 8.12 % E) 10 %

Rationale: "c . p . = 4700 + 800 = $ 5500 s . p . = $ 6400 gain = 6400 - 5500 = $ 900 gain % = 900 / 5500 * 100 = 16.36 % answer is b"
Answer: B