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?

What would be the concentration of $H_2SO_4$ necessary to precipitate $BaSO_4$ from a solution of $0.01 \ M \ Ba^{2+}$ ions $(K_{sp} = 1.0 \times 10^{-9})$?

Solid $Ba(NO_3)_2$ is gradually dissolved in $1.0 \times 10^{-4} \, M \, Na_2CO_3$ solution. At which concentration of $Ba^{2+}$ will the precipitation begin? $(K_{sp} \, BaCO_3 = 5.1 \times 10^{-9})$

The precipitation occurs if the ionic product is

Assign $A, B, C, D$ from the given type of reaction.
$2AgNO_3 + Na_2C_2O_4 \longrightarrow Ag_2C_2O_4 \downarrow + 2NaNO_3$

$A$ 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: $K_{sp}(SrCO_3) = 7.0 \times 10^{-10}$, $K_{sp}(SrF_2) = 7.9 \times 10^{-10}$