$3\mathrm{.}28$ A rinse tank at a chrome$-$plating shop has a volume of $1,000$ liters, and is

used to rinse hubcaps that have been chrome plated. The hubcaps each

drag in $0\mathrm{.}10$ L of plating solution which contains $90m\frac{g}{L}$ of chromium.

The hubcaps get rinsed at a rate of $12$ hubcaps per minute. Pure fresh

water is used for the rinse, and flows into the rinse tank continuously at a

rate of $200\frac{L}{m}in.$ The rinse tank discharges $200\frac{L}{m}in$ of used rinse

water, and the hubcaps drag out $0\mathrm{.}10$ L of used rinse water per hubcap.

Calculate the steady$-$state concentration of chromium in the discharged

rinse water, in $m\frac{g}{L}.$ Be sure to draw your diagram before you start.