Firstly thanks for all the input, I wasn't expected this much help for my little mathematical conundrum.

Quoting Yellowstone (Reply 4):
*What you want to use here is something called Newton's method.* |

I was actually studying it this week, when I was trying the fluids problem I hadn't really gone over my maths note yet. Seems to bring a bit of order to my "lets just throw in some values" method.

Quoting Fabo (Reply 5):
*Why repeat? If I understood right, you can use limit. You should get to about 1.96467 if I am not mistaken* |

By using a limit you mean with Newton's method? The version we learned didn't use that, I'll look around but if I misunderstood you I'll be on a wild goose chase for nothing.

Quoting Fabo (Reply 5):
*I will try figuring out how to isolate a, but do not expect much from me right now...* |

Don't worry if you're busy, I understand and thanks for your input.

Quoting BMI727 (Reply 3):
*Perhaps looking at the differential equations for a mixing problem would be of help.* |

I derived a differential equation. The one I derived was:

Q_out - Q_in = A_tank * (dh/dt) where Qs are volume flow rates, A is area and h is the height of water level in the tank.

On working it out using a given result printed under the question itself I ended up with the 2.64 = lna +a.

Not sure if you are referring to the same thing.

Once again thanks a million, very helpful.

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