Which of the following has the maximum solubility? (Given $K_{sp}$ values)

Assertion : Addition of silver ions to a mixture of aqueous sodium chloride and sodium bromide solution will first precipitate $AgBr$ rather than $AgCl$.
Reason : $K_{sp}$ of $AgCl < K_{sp}$ of $AgBr$.

The solubility product of $BaCl_2$ is $4 \times 10^{-9}$. Its solubility in $mol/L$ is .......

How many grams of $CaC_2O_4$ will dissolve in distilled water to make one litre of saturated solution (in $g$)? (Solubility product of $CaC_2O_4$ is $2.5 \times 10^{-9} \ mol^2 \ L^{-2}$ and its molecular weight is $128$)

Calculate the solubility in $mol \ dm^{-3}$ of sparingly soluble salt $BA$ if its solubility product is $4.9 \times 10^{-13}$ at the same temperature.

Calculate the solubility in $\text{mol dm}^{-3}$ of a sparingly soluble salt $BA$ at $293 \text{ K}$ if its solubility product constant $(K_{sp})$ is $8.56 \times 10^{-5}$ at the same temperature.