Find the compound interest on $1000 in 2years at 4% per annum, the interest being compounded half-yearly? Choose the correct answer:
A) $ 645.56  B) $ 82.43  C) $ 954.26  D) $ 745.69  E) $ 1020.45

Rationale: "principle = $ 10000 rate = 2 % half yearly = 4 half years amount = 1000 * ( 1 + 2 / 100 ) ^ 4 = 1000 * 51 / 50 * 51 / 50 * 51 / 50 * 51 / 50 = $ 1082.43 c . i . = 1082.43 - 1000 = $ 82.43 answer is b"
Answer: B