Answer:
After the passage of a month, the interest that Tori must pay will be $ 4.81.
Explanation:
Given that Tori has an unpaid balance of $ 300 on her credit card, and that said credit card has an annual interest of 21% on the unpaid balances, considering that the minimum payment is $ 25, to determine how much she should pay after a month of After your debt, it is necessary to perform the following calculation: 
12 = 21 
1 = X 
21/12 = X 
1.75 = X 
((300 - 25) x 1.75 / 100) + 300 = X 
4.81 + 300 = X 
304.81 = X 
Thus, after the passage of a month, the finance charge that Tori must pay will be $ 4.81.