Michelle deposited a certain sum of money in a savings account on July 1st, 2007. She earns an 6.4% interest compounded semiannually. The sum of money in the account on December 31st, 2009 is approximately what percent of the initial deposit? Choose the most appropriate option
A) 117 %	B) 120 %	C) 121 %	D) 135 %	E) 140 %

Rationale: since michelle earns 6.4 % interest compounded semiannually , then she earns 3.2 % interest every 6 months . now , the simple interest earned in 5 periods ( 30 months = 5 * 6 months ) would be 3.2 % * 5 = 16 % . but , since the interest iscompoundedevery 6 months , then there would be interest earned on interest ( very small amount ) thus the actual interest earned would be a little bit more than 16 % , only answer choice a fits . answer : a
Answer: A