LKD Co$.$ has $8$ percent coupon bonds with a YTM of $6\mathrm{.}8$ percent. The current yield on these bonds is $7\mathrm{.}4$ percent. How many years do these bonds have left until they mature? $($Do not round intermediate calculations. Round your answer to $2$ decimal places.$)$

Both Bond A and Bond B have $6$ percent coupons and are priced at par value. Bond A has $5$ years to maturity, while Bond B has $15$ years to maturity.

a$.$ If interest rates suddenly rise by $2$ percent, what is the percentage change in price of Bond A and Bond B$?($A negative value should be indicated by a minus sign. Do not round intermediate calculations. Enter your answers as a percent rounded to $2$ decimal places.$)$

b$.$ If interest rates suddenly fall by $2$ percent instead, what would be the percentage change in price of Bond A and Bond B$?($Do not round intermediate calculations. Enter your answers as a percent rounded to $2$ decimal places.$)$A bond sells for $$902\mathrm{.}30$ and has a coupon rate of $6$ percent. If the bond has $12$ years until maturity, what is the yield to maturity of the bond? Assume semiannual compounding. $($Do not round intermediate calculations. Enter your answer as a percent rounded to $2$ decimal places.$)$