Correct Answer - 7

As `K_(sp)` of CuCl is much greater than that of AgCl, `Cl^(-)` ions present in the mixture solution are mainly from CuCl and equal to `sqrt(10^(-6))`, i.e., `10^(-3) M`.

If `[Ag^(+)]= y "mol" L^(-1)` , then

`K_(sp) (AgCl) = [Ag^(+)][Cl^(-)]`

i.e., `1.6xx10^(-10) = y xx 10^(-3) or y = 1.6 xx 10^(-7)` . Hence , x = 7 .