An ideal steady$-$state completely mixed flow reactor $($CMFR$)$ with a hydraulic volume of $V=10,000m^3$ is used to remove a target contaminant. The flow rate is $Q=50,000\frac{m^3}{d}$ and the influent contaminant concentration is $C_l=10m\frac{g}{L}.$ You can assume the contaminant is removed in the reactor according to a first$-$order reaction with a rate constant of $k=0\mathrm{.}02mi{n}^{-1}.$

a$.$ Calculate the hydraulic residence time, $,$ in minutes.

b$.$ Calculate the effluent contaminant concentration, $C_E,$ in $m\frac{g}{L}.$