An enterprise obtained a loan of 80,000 yuan with a repayment period of 4 years and an annual interest rate of 10%. Try to calculate the annual repayment amount (principal and interest) of the following four repayment methods, 4. Four methods are commonly used: First, repay a certain amount of principal and current interest. Second, equal repayment of principal and interest. 3. Pay interest every year and repay the principal when due. Fourth, repay the principal and interest at maturity. The calculation is as follows:

First, when the payment column is the answer to the first case:

Balance at the beginning of the year, current interest, liabilities at the end of the year, and average annual principal repayment.

1 80000 8000 28000 60000 20000

2 60000 6000 26000 40000 20000

3 40000 4000 24000 20000 20000

4 20000 2000 22000 0 20000

The total is 2000080000.

Second, the column when paying principal and interest is the answer to the second case.

Balance at the beginning of the year, interest this year, liabilities at the end of the year, principal and interest this year.

1 80000 8000 17237.664 62762.336 25237.664

2 62762.336 6276.2336 1896 1.4304 43800.9056 25237.664

3 43800.9056 4380.09056 20857.57344 22943.332 16 25237.664

4 22943.332 16 2294.3332 16 22943.33078 0.00 1376 25237.664

Total: 20950. 36850 . 68686868686

Three, this column of interest and payment this year is the answer to the third case.

At the beginning of the year, the interest balance of the current year is paid in the current year.

1 80000 8000 0

2 80000 8000 0

3 80000 8000 0

4 80000 8000 80000

The total is 3200080000.

Four, the annual debt service column is the answer to the fourth situation.

Balance at the beginning of the year, interest this year, principal and interest this year.

1 80000 8000 0 0

2 88000 8800 0 0

3 96800 9680 0 0

4 106480 10648 80000 90648

Total 37128 80000117128.