$($b$).(1)$ Given the following spot rates of interest, $S_1=9\%$ and $S_2=10\%,$ calculate the Forward Rate $f_{12}$

$(10)$ A bond with a face value of $100,$ with coupon rate of $8\%$ and maturity period of two years and redeemable at par is sold at par value. Calculate it's yield to maturity.