NO.PZ2023091701000059
问题如下：
Bennett Bank extends a 5% APR (annual percentage rate) USD 100,000 30-year mortgage requiring monthly payments. If the mortgage is structured so that it requires interest-only payments for the first 5 years, after which point it becomes a self-amortizing mortgage, what would be the portion of the monthly payment applied to the principal in the 61st month?
选项：
A.USD 167.92
B.USD 174.60
C.USD 584.59
D.USD 591.27
解释：
老师好，等额本息的还款方式，每月月供的本金和利息均会发生变化对吧？也就是第61个月还的利息是10万*0.05/12，但第62个月，利息就变少了，本金就变多了，那第62个月的利息怎么求呢？
