The bacteria A$-88$ is described by a simple Monod equation, where ${}_{\text{m}\text{a}\text{x}}=0\mathrm{.}62h{r}^{-1},K_S=3\mathrm{.}8\frac{g}{L},$ and $Y_{CS}=0\mathrm{.}60.$

The bacteria will be cultivated in a CSTR with a $620\frac{L}{h}r$ feed rate and a substrate concentration of $80\frac{g}{L}.$ The exiting concentration of the substrate is $6\frac{g}{L}.$

$($a$)$ Calculate the volume of the CSTR$.$

$($b$)$ Calculate the exiting cell concentration.

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