a). If $3000 is deposited at the end of each half year in an account that earns 6.6% compounded semiannually, after how many half years will the account contain $100,000? (Round your answer UP to the nearest half year.) half years

b). Find the future value of an annuity due of $9,000 paid at the beginning of each 6-month period for 9 years if the interest rate is 4%, compounded semiannually. (Round your answer to the nearest cent.) $

c). How much must be deposited at the beginning of each year in an account that pays 6%, compounded annually, so that the account will contain $28,000 at the end of 4 years? (Round your answer to the nearest cent.) $