Paul's credit card closes on the 14th of the month and his payment is due on the 25th . If he purchases a $300 stereo on the 18th , how many interest days will he have? I need the answer and how you answered it? Thank you so much!

To determine the number of interest days Paul will have, we need to consider the billing cycle and payment due date.

1. First, calculate the number of days between the purchase date (18th) and the credit card closing date (14th) of the following month:
- Days between the 18th and the end of the month: 31 - 18 = 13 days
- Days between the 1st and the credit card closing date (14th) of the following month: 14 - 1 = 13 days

2. Since the credit card statement closes on the 14th and the purchase was made on the 18th, Paul will have four days of interest (from the 15th to the 18th).

3. However, we need to consider the payment due date (25th) as well. If Paul pays off the full balance of $300 on or before the due date, he won't have any interest days.

So the answer depends on when Paul pays off the $300 stereo:
- If Paul pays off the full balance on or before the due date (by the 25th): 0 interest days.
- If Paul does not pay off the full balance by the due date: 4 interest days (from the 15th to the 18th).

Therefore, the number of interest days Paul will have while purchasing the $300 stereo on the 18th depends on whether he pays off the balance before or on the due date.