An infinite sheet of charge is located in the yz plane at x $=0$ and has an uniform charge density $x_{}1=0\mathrm{.}330$ μC$/m2.$Another infinite sheet of charge with uniform charge density $x_{}2=-0\mathrm{.}470$ μC$/m2$ is located at

x$=$ c $=39\mathrm{.}0$ cm$.$ An uncharged infinite conducting slab is placed halfway in between these sheets $($i$.$e$.,$ between x $=$ a $=17\mathrm{.}5$ cm and x $=$ b $=21\mathrm{.}5$ cm$).$ 

 

What is the potential difference $V_{PS}$ between point P located at $($x$,$y$)=(\frac{1}{2}$a$,0)$ and point S located at $($x$,$y$)=(c-\frac{1}{2}a,-d)?$