Two capacitors of $2\mathrm{\mu F}$ and $3\mathrm{\mu F}$ are charged to 150 volt and 120 volt respectively. The plates of capacitor are connected as shown in the figure. An uncharged capacitor of capacity $1.5 \mathrm{\mu F}$ falls on the free ends of the wire. Then 

When the capacitor of capacity$1.5\mathrm{\mu F}$ comes into contact with $2\mathrm{\mu F}$and $3\mathrm{\mu F}$, the charge distribution takes place as shown below. Applying loop law, OPBDO,
$\frac{\mathrm{q}}{1.5}-\frac{360-\mathrm{q}}{3}-\frac{300-\mathrm{q}}{2}=0\Rightarrow 4q-720+2q-900+3q=0$

$\Rightarrow 9q=1620\Rightarrow q=180\mu C$

Charge on the $1.5\mu F$  capacitor is $q=180\mu C$
Charge on the $2\mu F$  capacitor is $\left(300-q\right)\mu C=120\mu C$