Answer
$q_2=3.33\times10^{-4}C$
Work Step by Step
We know that
$q_2=\frac{C_1C_2V}{C_1+C_2}$
Thus, we plug in the known values to obtain:
$q_2=\frac{10\times10^{-6}\times5\times10^{-6}\times100}{10\times10^{-6}+5\times10^{-6}}$
$q_2=3.33\times10^{-4}C$