A BOD test was conducted for an industrial wastewater. The wastewater portion added to the $300mL$ BOD bottle was $20\mathrm{.}0mL.$ At $t=0($right after dilution$),$ the $DO$ of the diluted wastewater sample was $8\mathrm{.}55m\frac{g}{L},$ and the DO of a BOD bottle filled with seeded dilution water was $8\mathrm{.}65m\frac{g}{L}.$ After $5$ days of incubation at $20C,$ the DO of the diluted wastewater sample was $2\mathrm{.}75m\frac{g}{L}$ while the DO of the solution in the bottle containing only seeded dilution water was $8\mathrm{.}39m\frac{g}{L}.$ Based on this information, the $BO{D}_5$ of the industrial wastewater $($in units of $m\frac{g}{L})$ was most nearly?

A$.5\mathrm{.}8{10}^0$

B$.6\mathrm{.}4{10}^0$

C$.5\mathrm{.}6{10}^1$

D$.5\mathrm{.}8{10}^1$

E$.8\mathrm{.}3{10}^1$

A wastewater has a $BO{D}_5$ of $150m\frac{g}{L}$ with a rate constant $($base e$),k=0\mathrm{.}15d^{-1}.$ The ultimate BOD$(BO{D}_u)$ in units of $m\frac{g}{L}$ will be most nearly?

A$.1\mathrm{.}3{10}^2$

B$.1\mathrm{.}5{10}^1$

C$.2\mathrm{.}8{10}^2$

D$.3\mathrm{.}7{10}^2$

E$.4\mathrm{.}8{10}^2$

Based on the information provided in the preceding problem, the BOD remaining $($unexerted$)$ after $5$ days incubation would be most nearly?

A$.1\mathrm{.}5{10}^1$

B$.1\mathrm{.}3{10}^2$

C$.2\mathrm{.}8{10}^2$

D$.3\mathrm{.}7{10}^2$

E$.4\mathrm{.}8{10}^2$