A woman is selling some land, and she will be paid a lump sum of $80,000 in 6 years. Until then, the buyer pays 7% simple interest quarterly. (a) Find the amount of each quarterly interest payment. (b) The buyer sets up a sinking fund so that enough money will be present to pay off the $80,000. The buyer wants to make semiannual payments into the sinking fund; the account pays 6% compounded semiannually. Find the amount of each payment into the fund