1. Find the amount of a 25-year mortgage at 4.2% interest compounded monthly where the monthly payment is $1121.00.
2. A 30-year mortgage at 4.2% interest compounded monthly with a monthly payment of $1019.35 has an unpaid balance of $10,000 after 350 months. Find the unpaid balance after 351 months.
3. A 25-year mortgage at 4.5% interest compounded monthly with a monthly payment of $258.96 has an unpaid balance of $5,000 after 280 months. Find the unpaid balance after 281 months?