$($Construction of a zero$-$coupon$)$ Consider two $8-$year bonds: bond A has a $8\%$ coupon

and sells for $99\mathrm{.}832$ ; bond $B$ has a $6\%$ coupon and sells for $88\mathrm{.}074.$ Both bonds have the

same face value, normalized to $100.$ Find the spot rate $s_8.$