Answer
$Q=0.110\mu C$
Work Step by Step
We know that
$U=\frac{1}{2}\frac{Q^2}{C}$
This formula can be rearranged as:
$Q=\sqrt{2CU}$
We plug in the known values to obtain:
$Q=\sqrt{2\times 340\times 10^{-6}\times 17.9\times 10^{-12}}=0.110\times 10^{-6}=0.110\mu C$
