12. 
Katherine runs her own pizza shop. For each pizza, it costs her $2.21 for ingredients, $1.24 for overhead, and $0.47 for mailing flyers. She charges $5.84 per pizza. As a percentage of her costs, how much profit does Katherine earn for each pizza she sells?


13. 
Emma invested money at Party Bank three years ago. She signed up for a CD that paid 6% yearly interest, compounded semiannually. The interest is added to the balance and is accumulated with the original investment. At the end of three years, her account is worth $4,417.99. How much was her initial investment?

