Tim went shopping last month and spent $1,000 on a new credit card with a 19% APR. He wants to pay it off before making new purchases on the card. He doesn't worry about it too much and plans to pay the minimum amount of $25 per month until the card is paid off. After five months, how much will Tim have paid an interest so far and how much will still have to pay back? Use the formulas below to calculate his interest and balance for each month.