A sum of money deposited at C.I. amounts to Rs.2560 in 3 years and to Rs.2989 in 4 years. Find the rate percent?	Options.
A) 30 %	B) 10 %	C) 20 %	D) 16 %	E) 50 %

Rationale: "2560 - - - 429 100 - - - ? = > 16 % answer : d"
Answer: D