The principal and interest are still more than 10000, for example 10000.

Interest = 10000-6000=4000 yuan.

Interest = principal x interest rate x term

4000=6000x interest rate x2

Interest rate =0.3333333

Monthly interest =0.0277778. Generally speaking, the monthly interest rate is 2.7, which is four times higher than the bank loan interest rate for the same period. It is usury, and the excess is not protected by law.