A sum of money deposited at C.I. amounts to Rs.9000 in 10 years and to Rs.9990 in 11 years. Find the rate percent?
Choose the correct answer.
A) 9 % B) 10 % C) 11 % D) 12 % E) 13 %

Rationale: "9000 - - - 990 100 - - - ? = > 11 % answer : c"
Answer: C