The table below shows data from real test runs for three membranes tested under $3$ different conditions $($Cases A$,$ B and C$).$ Using the data below, compute

the $($a$)$ steady state CO$2$ permeance $($in GPU$)$ and $($b$)$ CO$2/$CH$4$ selectivities for the three casesL$=$ length of the hollow fiber membrane used $cm)$

$OD=$ outer diameter of the fiber used $(cm)$

$P_{\text{f}\text{e}\text{e}\text{d}}=$ Total feed pressure $($psia$)$

$V_p=$ volume of permeate collected $(mL)$

$t=$ time to collect $(s)$

$Y_{cO2}=C{O}_2$mol$\%$ in permeate stream $(\%)$