It is calculated based on the loan interest rate. Loan interest = loan principal * loan annual interest rate * loan term.

1. If the annual interest rate of the loan is 3%, the loan interest = 1600*5%*23 years, and the interest is 1840 yuan.

2. If the annual interest rate of the loan is 5%, the loan interest = 1600*3%*23 years, and the interest is 1104 yuan.