The actual annual interest rate of the loan is 35.8757%, and the calculation formula is as follows:

Let the actual annual interest rate r and the monthly interest rate R/ 12 give:

25000*r/ 12*( 1+r/ 12)^ 12/[( 1+r/ 12)^ 12- 1]=25 10

R = ratio (12,--25 10, 25000)* 12=35.8757%.

Description: 12 is the power of 12.