A solution containing a mixture of $0.05 \mathrm{M} \mathrm{NaCl}$ and 0.05 M Nal is taken (${\mathrm{Ks}}_{\mathrm{p}}$ of $\mathrm{AgCl} = {10}^{-10}$ and ${\mathrm{Ks}}_{\mathrm{p}}$ of$\mathrm{Agl} = 4 \mathrm{x} {10}^{-18}$ ). When ${\mathrm{AgNO}}_3$ is added to such a solution:

AgCl and Agl will be precipitated together.

the concentration of ${\mathrm{Ag}}^{+}$ that can just precipitate ${\mathrm{I}}^{-}=8\times {10}^{-17}\mathrm{mol}/\mathrm{L}$

first Agl will be precipitated.

the concentration of ${\mathrm{Ag}}^{+}$ that can just precipitate ${\mathrm{Cl}}^{-}=2\times {10}^{-9}\mathrm{mol}/\mathrm{L}$