65,438+0,600,000 yuan, the interest is 400,000 yuan for three years, and the interest rate is 8.33%, because the interest of 65,438+0,600,000 yuan for three years is 400,000 yuan for one year, and the interest of 400,000 yuan divided by three equals 65,438+0.

Interest rate refers to the ratio of interest amount to the amount of borrowed funds in a certain period, which is usually calculated as the percentage of one-year interest to principal.