Answer
The charge on the left plate of each capacitor is $~~+\frac{CV}{3}$
Work Step by Step
In part (a), we found that the potential difference across each capacitor is $\frac{V}{3}$
We can find the magnitude of the charge on each plate:
$q = (C)(\frac{V}{3})$
$q = \frac{CV}{3}$
Since the right side of the battery is the negative side, the right plate of each capacitor will have a negative charge, and the left plate of each capacitor will have a positive charge.
The charge on the left plate of each capacitor is $~~+\frac{CV}{3}$.
