Number of compounding periods is n=12months×3years=36 I assume that
The total interest= monthly payment×number of compounding periods - the amount of the present value of an annuity ordinary I=x×n-pv
Let monthly payment be X
I =Total interest is 1505.82
The present value of an annuity ordinary is Pv=X [(1-(1+0.09/12)^(-36))÷(0.09/12)]
now plug those in the formula of the total interest above I=x×n-pv 1505.72=36X-X [(1-(1+0.09/12)^(-36))÷(0.09/12)] Solve for X using Google calculator to get the monthly payment which is X=330.72
Check your answer using the interest formula 36×330.72−330.72×((1−(1+0.09 ÷12)^(−12×3))÷(0.09÷12)) =1,505.83
