I get the same system of differencial equations.
Unless you want me explain how those numbers come from if you were not sure.
Solve the mixing problem. At t = 0, the volume of solution in both tanks is 60 L and tank 1 contains 60 g of chemical whereas tank 2 contains 200 g of chemical.
The system of differential equations I ended up getting is:
Is this right? How would I solve this?