Space between the plates of a parallel plate capacitor of plate area 4 cm^2 and separation of (d) 1.77 mm, is filled with uniform dielectric…

Space between the plates of a parallel plate capacitor of plate area $\displaystyle 4 \mathrm{~cm}^2$ and separation of (d) $\displaystyle 1.77$ mm, is filled with uniform dielectric materials with dielectric constants ($\displaystyle 3$ and $\displaystyle 5$)as shown in figure. Another capacitor of capacitance $\displaystyle 7.5$ pF is connected in parallel with it. The effective capacitance of this combination is $\displaystyle \_\_\_\_$ pF. (Given $\displaystyle \epsilon_{\mathrm{o}}=8.85 \times 10^{-12} \mathrm{~F} / \mathrm{m}$ )