The monthly repayment rate is 7.95%/ 12 = 0.6625%, and the loan amount is 300,000 yuan. Use the function of excel to calculate, and input in excel:
=PMT(0.6625%，240，-300000，0)
Calculated, the monthly repayment amount is 2499.99 yuan, about 2500 yuan.
If the loan interest rate suddenly drops to 6.5%, the monthly repayment amount is 0, which is entered in excel.
=PMT(6.5%/ 12，240，-300000，0)
The monthly repayment is 2236.72 yuan, and the monthly repayment is 263.27 yuan less.
In these 20 years, the total repayment before interest rate reduction =2499.99*240=599998.30 yuan,
Total repayment after interest rate reduction =2236.72*240=5368 12.66 yuan,
Both totals include the principal of 300,000 yuan, so the extra interest is interest, that is, the interest paid is 63 185.64 yuan.
If the repayment is still 2499.99 yuan per month after the interest rate cut, the number of repayment months is, and enter in excel:
=NPER(6.5%/ 12，2499.99，-300000，0)
A * * * repayment month is 194.34 months, which means it can be paid off in 195 months. That is, 16 still has three months to pay off. Pay off 3 years and 9 months in advance.
The total repayment amount is 2499.99 *194.34 = 485845.88 yuan, and the underpaid interest amount is 599998.30-485845.88 =14152.42 yuan.
There are too many topics. Find a way to solve Mr. Li's retirement problem first. Let me see your thoughts and results.