Solubility of $AgCl$ in $0.2 \, M \, NaCl$ is $x$ and that in $0.1 \, M \, AgNO_3$ is $y$. Then which of the following is correct?

Calculate the solubility product of sparingly soluble salt $BA$ at $27^{\circ} C$ if its solubility is $1.8 \times 10^{-5} \ mol \ dm^{-3}$ at same temperature.

The compound insoluble in water is

The solubility of $BaSO_4$ in pure water (in $g \, L^{-1}$) is closest to
[Given: $K_{sp}$ for $BaSO_4$ is $1.0 \times 10^{-10}$ at $25^{\circ} C$. Molecular weight of $BaSO_4$ is $233 \, g \, mol^{-1}$]

The solubility product of sparingly soluble salt $AX_{2}$ is $3.2 \times 10^{-11}$. Its solubility (in $mol / L$) is

The solubility products of three sparingly soluble salts $AB$,$A_2B$ and $AB_3$ are respectively $4.0 \times 10^{-20}$,$3.2 \times 10^{-11}$ and $2.7 \times 10^{-31}$. The increasing order of their solubility is