The formula which is used for determining the interest is as follows:

Present value = Cash payment in period One/(1 + interest)

If 8.2% is the coupon rate then for tri-annual payments 0.082/3 x 1200 is the payment of every period. Total payments in 3 years will be 9 payments.

Present value = Cash payment in period One/(1 + interest)

^{1}+ Cash payment in period One/(1 + interest)^{2 }+...If 8.2% is the coupon rate then for tri-annual payments 0.082/3 x 1200 is the payment of every period. Total payments in 3 years will be 9 payments.