${\mathrm{p}}^{\mathrm{H}}$ of a saturated solution of $\mathrm{M}{\left(\mathrm{OH}\right)}_2$ is 10. Solubility product of  ${\mathrm{M}\left(\mathrm{OH}\right)}_2$ will be

$$\begin{gathered} {\mathrm{p}}^{\mathrm{H}}=10;{\text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}p}}^{\mathrm{OH}}=4;\left[{\mathrm{OH}}^{-}\right]={10}^{-4}\mathrm{M} \\ \mathrm{M}{\left(\mathrm{OH}\right)}_2\rightleftharpoons \underset{ }{\underset{ }{ }}\underset{\left(\mathrm{S}\right)}{{\mathrm{M}}_{ }^{+2}}+\underset{\left(2\mathrm{S}\right)}{2{\mathrm{OH}}^{-}} \\ \mathrm{If}2\mathrm{S}={10}^{-4}\mathrm{S}=\frac{{10}^{-4}}{2} \\ {\mathrm{K}}_{\mathrm{SP}}\mathrm{of}\mathrm{M}{\left(\mathrm{OH}\right)}_2=\left(\frac{{10}^{-4}}{2}\right){\left({10}^{-4}\right)}^2 \\ =0.5\times {10}^{-12} \\ =5\times {10}^{-13} \end{gathered}$$