Find the difference between C.I and S.I on a sum of money Rs. 2000 for 2 years. at 4% p.a  Choose the correct answer:
A) rs . 2.20  B) rs . 3.20  C) rs . 4.20  D) rs . 5.20  E) rs . 3.25

Rationale: p 9 r / 100 ) ^ 2 = 2000 ( 4 / 100 ) ^ 2 = rs . 3.20 answer : b
Answer: B