$(40$ pts$)[$CSTR$]$ The reaction $AB,r=k{C}_A$ occurs in $n$ equal volume CSTRs in series, each with

residence time $,$ with $90\%$ overall conversion. If $k=0\mathrm{.}5mi{n}^{-1},C_{Ao}=2$ moles $/$liter$,$ and $v=4$ liters $/$min$,$

what would be residence times and reactor volumes for $n=1,2,3,$ and $4?$