Chemistry - Ionic Equilibrium Question with Solution | TestHub

For any sparingly soluble salt $\left[\mathrm{M}{\left({\mathrm{NH}}_3\right)}_4{\mathrm{Br}}_2\right]{\mathrm{H}}_2{\mathrm{PO}}_2$

Given: ${\lambda }_{\mathrm{M}({\mathrm{NH}}_3{)}_4{\mathrm{Br}}_2^{+}}^{\circ }=400\mathrm{S}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$, ${\lambda }_{{\mathrm{H}}_2{\mathrm{PO}}_2^{-}}^{\circ }=100\mathrm{S}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$.

Specific resistance of a saturated $[\mathrm{M}({\mathrm{NH}}_3{)}_4{\mathrm{Br}}_2]{\mathrm{H}}_2{\mathrm{PO}}_2$ solution is $200\Omega \mathrm{m}$.

If the solubility of the above salt is $10^{-x}\mathrm{M}$, what will be the value of $x$?