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People leaving and entering city

  1. Mar 5, 2010 #1
    (Moderator's note: thread moved from "Differential Equations")

    By natural increase, a city, whose population is 40,000, will double in 50 years. There is a net addition of 400 persons per year because of people leaving and moving into the city. Estimate its population in 10 years.

    My book gives an answer of 50,240, but I am not sure how to get here. Usually I would put up the work I've already done, but it's all waaayyy off. I have, however, only tried to tackle it the "standard" simplest way, and haven't yet tried introducing a change of variables.
    Last edited by a moderator: Mar 5, 2010
  2. jcsd
  3. Mar 5, 2010 #2


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    Hi tickle_monste! :wink:

    Show us your full calculations, and then we'll see what went wrong, and we'll know how to help! :smile:
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