What is functionality factor? Assuming a value of $0\mathrm{.}999$ for p $($extent of reaction$),$

what would be the DP of a polyester prepared from equimolar quantities of

difunctional reactants in the presence of $1\mathrm{.}5$ mol$\%$ of acetic acid? Let the mol$\%$

difunctional reactants both be $98\mathrm{.}5.$