Sandy buys an old scooter for $900 and spends $300 on its repairs. If Sandy sells the scooter for $1260, what is the gain percent?  Choices:
A) 3 %  B) 5 %  C) 7 %  D) 9 %  E) 11 %

Rationale: "selling price / total cost = 1260 / 1200 = 1.05 the gain percent is 5 % . the answer is b ."
Answer: B