1, the monthly interest rate of the fund is 3%, and the annual interest rate of 5% means 100 yuan: the former means the income of saving 3 yuan for one month; The latter is saved with 5 yuan's income for one year.

2. Concept introduction:

Interest, as far as its form is concerned, is the reward that the monetary owner gets from the borrower for issuing monetary funds; On the other hand, it is the price that the borrower must pay for using monetary funds. Interest is essentially a part of profit and a special form of profit transformation. Interest = principal × interest rate× deposit period (i.e. time).