The six$-$month and one$-$year zero rates are both $10\%$ per annum. For a bond that has a life of $18$

months and pays a coupon of $8\%$ per annum $($with semi$-$annual payments and one having just been

made$),$ the yield is $10\mathrm{.}4\%$ per annum.

$($a$)$ What is the bonds price?

$($b$)$ What is the $18-$month zero rate?

All rates are quoted with semi$-$annual compounding.

Can you please explain what the $18$ month zero rate is$?$ Is it a interest rate for the bond or coupon?