Serial dilutions $(6$ pts$.$ total$)$:

a$.$ A volume of $10\mathrm{.}0mL$ of $25m\frac{g}{L}M{n}^{2+}$ solution was diluted to make a solution with the final volume of $50\mathrm{.}0mL.$ Calculate the concentration $($in $m\frac{g}{L})$ of the final solution $(2pts).$

b$.$ Using $2\mathrm{.}0mL$ of the solution with a concentration from part a$,$ calculate the concentration of the result of a second dilution $-$ if the $2\mathrm{.}0mL$ volume were diluted to $5\mathrm{.}0mL(2$ pts$.).$

c$.$ What volume of $5\mathrm{.}0m\frac{g}{L}M{n}^{2+}$ would be needed to make $5\mathrm{.}0mL$ of a $1\mathrm{.}5m\frac{g}{L}$ solution $(2$ pts$.)?$