t an annual effective interest rate of i it is known that

$($i$)$ The PV of $2$ at the end of each year for $2$n years, plus an additional $1$ at the end of each of the first

n years, is $36.$

$($ii$)$ The PV of an n$-$year deferred annuity$-$immediate paying $2$ per year for n years is $6.$

Find i