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?

The values of $K_{sp}$ for $CuS$,$Ag_2S$ and $HgS$ are $10^{-31}$,$10^{-42}$ and $10^{-54}$ respectively. The correct order of their solubility in water is

$A$ salt $MX$ has $K_{sp} = 4 \times 10^{-10}$. What value of $K_{sp}$ must another salt $MX_3$ have if the molar solubility of the two salts is to be identical?

$A$ solution is saturated with $SrCO_3$ and $SrF_2$. The $[CO_3^{2-}]$ is found to be $1.2 \times 10^{-3} \ M$. The concentration of $F^{-}$ in the solution would be:
Given: $K_{sp}(SrCO_3) = 7.0 \times 10^{-10}$,$K_{sp}(SrF_2) = 7.9 \times 10^{-10}$

Solubility of $CaF_2$ in a solution of $Ca(NO_3)_2$ will be represented by the concentration term?

How many grams of $CaC_2O_4$ will dissolve in distilled water to make $1 \, L$ of a saturated solution (in $, g$)? The solubility product $(K_{sp})$ of $CaC_2O_4$ is $2.5 \times 10^{-9} \, mol^2 \, L^{-2}$ and its molar mass is $128 \, g \, mol^{-1}$.