Chlorination of benzene occurs via the following sequence:

C$6$H$6+$ Cl$2->$ C$6$H$5$Cl $+$ HCl

C$6$H$5$Cl $+$ Cl$2->$ C$6$H$4$Cl$2+$ HCl

C$6$H$4$Cl$2+$ Cl$2->$ C$6$H$3$Cl$3+$ HCl

The feed to the reactor contains benzene and chlorine. There are $30\mathrm{.}5$ mol of benzene, $20\mathrm{.}4$ mol chlorine and $40$ mol HCl in the product stream. The selectivity of dichlorobenzene to trichlorobenzene is $1\mathrm{.}8$ while the selectivity of dichlorobenzene to monochlorobenzene is $2\mathrm{.}2.$ Determine $($a$)$ extents of the reaction $($b$)\%$ composition of the reactant stream $($d$)$ fractional conversion of benzene $.$