As shown in the figure, two parallel plate capacitors having equal plate area of $200 \mathrm{~cm}^2$ are joined in such a way that $\mathrm{a} \neq \mathrm{b}$. The equivalent capacitance of the combination is $\mathrm{x} \in_0 \mathrm{~F}$. The value of x is $\_\_\_\_$ .
