Which of the following is least soluble in water?

If the solubility products of $AgCl$ and $AgBr$ are $1.0 \times 10^{-10}$ and $3.5 \times 10^{-13}$ respectively,then the relation between the solubilities (denoted by the symbol $S$) of these salts can correctly be represented as:

$150 \, mL$ of $0.0008 \, M$ ammonium sulphate is mixed with $50 \, mL$ of $0.04 \, M$ calcium nitrate. The ionic product of $CaSO_4$ will be ($K_{SP} = 2.4 \times 10^{-5}$ for $CaSO_4$)

If the concentration of $[Ag^{+}]$ in a solution is $1 \times 10^{-6} \ M$,what is the concentration of $[Br^{-}]$? Given that the $K_{sp}$ for $AgBr$ is $4.0 \times 10^{-13}$.

The solubility of a salt $A_2B_3$ is $10^{-3} \ M$. What will be its solubility product?

At $T(K)$,the solubility product of $AgBr$ is $4 \times 10^{-13}$. What is its solubility in $0.1 \ M$ $KBr$ solution?