Frank's Doughnut shop has a special deal. The first dozen
doughnuts cost $3.50. For every doughnut after that the
price is 15¢. Which formula best describes the cost C in
dollars of buying D doughnuts (assuming the D > 12)?
If we're finding the price of C, and D is equivalent to 12, 12 x 15 = 180, but we have a decimal point to the first numeral. Therefore, the answer would be $1.80