
$V$. Energy stored in the above combination is $\mathrm{E}$. When these capacitors are connected in series to the same supply, the stored energy is $\frac{9}{\mathrm{x}} \mathrm{E}$. The value of $x$ is___________.

(If initial charge is $q_{0}$ )
[permittivity of free space $ = 9 \times 10^{-12}\ Fm^{-1}$]