The volume of lake $=150×10^9Litre$
The flow rate in and out of the lake $=20×10^6 \frac{Liter}{year}$
Concentration, $C(t)=4+sin(2t)\frac{grams}{Litre}°$
Assumptions: Pollution not created or destroyed in the lake , Lake is well mixed.
Form a differential equation describing this contamination flow and determine the amount $Q(t)$ of toxic chemicals in the lake at time $t$.
so yeah I am lost as to where to even start, I have researched other models but they all solve for C(t) so any and all help is welcomed, links or videos to read/watch as well.
thank you for your time
