利率5%with monthly compounding的话， I/Y不能直接5➗12吧？

问题如下：

What is the monthly payment on a 15-year mortgage where the rate is 5% with monthly compounding and the amount borrowed is USD 100,000?

解释：

The monthly payment, X, satisfies

X/(0.05/12)×[1-1/(1+0.05/12)^(12×15)]=100,000

Solving this gives X equal to USD 790.79.

一个15年的mortgage，月利息是5%，本金是100000，每月的还款金额是多少？

我们默认mortgage是fulluy amortizated的

PV=100000，FV=0，N=15*12=180，I/Y=5/12=0.416667

CPT-->PMT=790.79