One day is 3 yuan.

According to the meaning of the question, the loan principal is 1, yuan, that is, 1, yuan,

The interest is three thousandths of a day, and the current interest rate is .3%

According to the formula, daily interest = principal * daily interest rate

is substituted into the data in the question. The following formula can be obtained:

daily interest =1*.3%=3 (yuan)

Extended information:

interest (year) = principal × annual interest rate (percentage) × deposit period

or interest = principal× interest rate× time. Housing provident fund loans and commercial personal housing loans of most banks have adopted this method. This way, the monthly repayment amount is the same;

(2) repayment of equal principal: that is, a repayment method in which the borrower evenly distributes the loan amount to each installment (month) throughout the repayment period and pays off the loan interest from the previous trading day to the repayment day. In this way, the monthly repayment amount decreases month by month;

(3) Pay interest on a monthly basis and repay the principal at maturity: that is, the borrower will repay the loan principal in one lump sum on the loan maturity date (applicable to loans with a term of less than one year (including one year)), and the loan will bear interest on a daily basis and the interest will be repaid on a monthly basis;

(4) early repayment of part of the loan: that is, the borrower can repay part of the loan amount in advance when applying to the bank, generally the amount is 1, or an integer multiple of 1,. After repayment, the loan bank will issue a new repayment plan, in which the repayment amount and repayment period are changed, but the repayment method is unchanged, and the new repayment period shall not exceed the original loan period.

(5) early repayment of all loans: that is, the borrower can repay all the loan amount in advance when applying to the bank. After repayment, the loan bank will terminate the borrower's loan and handle the corresponding cancellation procedures.

(6) Pay back as you borrow: the interest after borrowing is calculated on a daily basis, and the interest is calculated on a daily basis. You can settle the money in one lump sum at any time without penalty.