Final answer:
Greg would save $898.75 by opting to pay $50 a month compared to the minimum payments over an extended period due to lower total interest paid.
Step-by-step explanation:
Greg would save money by opting to pay a fixed amount of $50 a month instead of the minimum payment on his credit card debt. Calculating his savings involves comparing the total interest paid under both repayment plans. The total interest paid when paying $50 a month for 20 months comes to $139.33. In contrast, paying the minimum payment over 124 months results in $1,038.08 in total interest.
To find out how much Greg would save, subtract the total interest paid with $50 monthly payments from the total interest paid with the minimum payments: $1,038.08 - $139.33 = $898.75. Therefore, Greg would save $898.75 by paying $50 a month instead of the minimum payment.