Answer:
Jill has to pay US$ 413.64 in addition when the interest rate changes from 5% to 10% on the US$ 5,000 balance
Explanation:
1. Let's review the information given to us to answer the question correctly:
Minimum monthly payment Jill have to make to pay the balance of US$ 5,000 with an annual interest rate of 10% = US$ 161.34
Minimum monthly payment Jill have to make to pay the balance of US$ 5,000 with an annual interest rate of 5% = US$ 149.85
Time it takes pay totally the US$ 5,000 on both credit cards = 3 years
2. How much more does Jill have to pay when the interest rate changes from 5% to 10% on the $5,000 balance?
To find the difference between the two credit cards monthly payments, we make this calculation:
Difference = Minimum monthly payment Jill have to make to pay the balance of US$ 5,000 with an annual interest rate of 10% - Minimum monthly payment Jill have to make to pay the balance of US$ 5,000 with an annual interest rate of 5%
Difference = 161.34 - 149.85
Difference = US$ 11.49 per month
Now, for calculating how much more Jill has to pay when the interest rate changes from 5% to 10% on the US$ 5,000 balance, we use this multiplication:
Monthly difference * 3 years = monthly difference * 36 months
= 11.49 * 36 = 413.64
Jill has to pay US$ 413.64 in addition when the interest rate changes from 5% to 10% on the US$ 5,000 balance