ONLY NEED PART C ANSWERED$/$ EXPLAINED PLEASE!!!!

a$.$ Determine percent particle removal that could be achieved using a rectangular, horizontal flow sedimentation basin of length $100$m$,$ depth $5$m$,$ and width $5$m$.(85\mathrm{.}3)$

b$.$ Detention time $($h$)$ of the rectangular sedimentation basin. $(3\mathrm{.}82$ h$)$

c$.$ Horizontal flow velocity $($m$/$min$)$ in rectangular sedimentation basin.