what is the cocnetration

A well-mixed lake with a volume, Vw=1011m3 receives a constant inflow of wastewater, Qww =103m3d1 containing Ciwin=10mgm3 of the anti-diabetes drug metformin (structure below). The flowthrough of the lake, Qw=104m3d1. a. If flushing is the only removal process, what is the steady-state concentration (Ci) of metformin in the lake? b. What is the steady-state concentration (Ci) of metformin in the lake be if the compound also underwent transformation with a pseudo-first-order rate constant, kireaction=108s1