Penicillin F is recovered from a dilute aqueous fermentation broth by extraction with amyl acetate, using $6$ volumes of solvent per $100$ volumes of the aqueous phase. At pH $=3\mathrm{.}2$ the distribution coefficient Kd is $80.$

$1.$ What fraction of the penicillin would be recovered in a single ideal stage? $2.$ What would be the recovery with two$-$stage extraction using fresh solvent in both stages?