$($a$)$ When a battery is connected to the plates of a $4\mathrm{.}00-$F capacitor, it stores a charge of $72\mathrm{.}0$C$.$ What is the voltage of the battery?

V

$($b$)$ If the same capacitor is connected to another battery and $60\mathrm{.}0$C of charge is stored on the capacitor, what is the voltage of the battery?

V