In 1 L saturated solution of AgCl, $\left[{\mathrm{K}}_{\mathrm{sp}}\left(\mathrm{AgCl}\right)=1.6\times {10}^{-10}\right]$ 0.1 mole of $\mathrm{CuCl}\left[{\mathrm{K}}_{\mathrm{sp}}\left(\mathrm{CuCl}\right)=1.0\times {10}^{-6}\right]$ is added. The resultant concentration of Ag⁺ in the solution is 1.6 x 10 ^{- x}. The value of x is

It is a case of simultaneous solubitity of salts with a common ion. Here ,solubility product of CuCl is much greater than that of AgCl, it can be assumed that Cl^- in solution comes mainly from CuCl.
$\left[{\mathrm{Cl}}^{-}\right]=\sqrt{{\mathrm{K}}_{\mathrm{sp}}\left(\mathrm{CuCl}\right)}={10}^{-3}\mathrm{M}$
$\text{ For }\mathrm{AgCl},{\mathrm{K}}_{\mathrm{sp}}=1.6\times {10}^{-10}$
$$\begin{gathered} =\left[{\mathrm{Ag}}^{+}\right]\left[{\mathrm{Cl}}^{-}\right] \\ =\left[{\mathrm{Ag}}^{+}\right]\times {10}^{-3} \\ =\left[{\mathrm{Ag}}^{+}\right]=1.6\times {10}^{-7} \end{gathered}$$