Matching principal and interest method: loan principal: 300,000 yuan, assuming annual interest rate: 7.420%, loan life: 5 years, monthly repayment principal and interest amount: 5999.99 yuan, total repayment amount: 359,999.4 yuan, and * * repayable interest: 59,999.4 yuan. The interest paid in 1 month is:1855; The first 1 month principal repayment is: 4144.99; Since then, the monthly interest repayment amount has decreased and the principal has increased. (without considering the adjustment of interest rate in the middle)