A lake with constant volume 10 x 10^6 m^3 is fed by a pollution-free stream with flow rate 50 m^3/s. A factory dumps 5 m/s of a non conservative waste

with concentration 100 mg/L into the lake. The pollutant has a reaction rate coefficient K of 0.25/day.Assuming the pollutant is well mixed in the lake, find the steady-state concentration of pollutant in the lake.