1. Peggy Portzen purchased new kitchen appliances with a cash price of $6,800. After making a down payment of $900, she financed the balance over 24 months with payments of $279.65. Find the annual percentage rate (APR) of the loan.
2. The cash price of a music system is $2,859 and the instalment price is $3,115.35. How much is the finance charge?
3. Find the instalment payment for a trailer if its instalment price is $3,296.96 over 30 months and an $800 down payment is made.