$1.$ A $25-$year zero$-$coupon bond with face value of $$1,000$ is sold for $$850$ now, what is the YTM for this bond?

$2.$ A $15-$year $6\mathrm{.}5\%$ coupon $($semiannual$)$ bond sells for $$965,$ what is the bond holder$$s YTM$?$

$3.$ On the issue date, you bought a $30-$year maturity, $5\mathrm{.}85\%$ semi$-$annual coupon bond. The bond then sold at YTM of $6\mathrm{.}25\%.$ Now, $5$ years later, the similar bond sells at YTM of $5\mathrm{.}25\%.$ If you hold the bond now, what is your realized rate of return for the $5-$year holding period?