Answer:
The first step is to calculate the daily interest rate. We can do this by dividing the annual percentage rate (APR) by 365 (the number of days in a year):
Daily interest rate = 15% / 365 = 0.00041096
Next, we need to calculate the interest that accrues on the outstanding balance for the first month. Since there are 30 days in a typical month, we can multiply the daily interest rate by the outstanding balance and the number of days in the month:
Interest for first month = 0.00041096 × $400 × 30 = $4.93
This means that the outstanding balance after the first payment will be:
$400 + $4.93 - $75 = $329.93
So the balance after the first payment will be $329.93.