$30 \mathrm{mL}$ of $0.1 \mathrm{M}$ $\text{K}\text{I}(\text{a}\text{q})$ and $10 \mathrm{mL}$ of $0.2 \mathrm{M}$ $\text{A}\text{g}\text{N}{\text{O}}_3$ are mixed. The solution is then filtered out. Assuming no change in total volume, depression in freezing point of the resulting solution will be : (Given : ${\mathrm{K}}_{\mathrm{f} }$for ${\mathrm{H}}_2\mathrm{O} = 1.86 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$, assume molarity = molality)