- Interest and Yield
Simple Interest: Interest paid periodically as it comes due

*I*=_{n}*r*•*P*

*I*=_{total}*m*•*r*•*P*

*A*=*P*•(1 +*m*•*r*)*P*is the pricipal amount,*r*is the interest rate per payment period,*I*is the interest payment for the_{n}*n*payment period,^{th}*m*is the number of payment periods and I_{total}is the total interest paid.*A*is the total return on the investment once the pricipal is paid at the end.Compound Interest: Interest added to the amount of the loan

*P*_{0}=*P*

*I*=_{n}*r*•*P*_{n-1}

*P*=_{n}*P*_{n-1}+*I*_{n}

*A*=*P*•(1 +*r*)^{m}

*I*=_{total}*A*-*P*=*P*•((1 +*r*)^{m}- 1)

*effective rate**r*= (1 +_{effective}*r*)^{m}- 1