Typical Mixing Tank Problem ODE

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mitchaldichter...
The most common differential equation mixing problem is a tank of water with salt water being poured in at the same rate water is flowing out of the tank. There are a few variations which are all typical homework exercises in an introductory differential equations course. A real world application is polluted water flowing into a large lake which also has an outlet, solving the ODE to determine how polluted the water will be over time.