Two charges of 5 Q and - 2 Q are situated at the points ( 3 a , 0 ) and ( - 5 a , 0 ) respectively. The…

As can be seen from the figure above, only the $5Q$ charge is inside the spherical region.

The formula to calculate the flux through the surface is given by

$\varphi =\frac{q_{\mathrm{enc}}}{{\epsilon }_0} ...\left(1\right)$

From equation $\left(1\right)$, the flux through the given surface can be calculated as follows:

$\varphi =\frac{5Q}{{\epsilon }_0}$