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Homework Help: Exponential Function?

  1. Apr 18, 2009 #1
    1. The problem statement, all variables and given/known data
    Species A doubles every 2 hours and initially there are 6 grams. Species B doubles every 5 hours and initially there are 14 grams.

    2. Relevant equations

    3. The attempt at a solution
    I've tried graphing this, but I don't think I have the right equations down. I don't know how to form the equations so I can solve the problem.
  2. jcsd
  3. Apr 18, 2009 #2
    In general for 'doubling time' problems, we have a simple formula

    [tex]N = N_0 \times 2^{t \over T}[/tex]

    where N is the number of bacteria after t minutes and T is the time in minutes that it takes to double.

    So if that's the relevant equation, attempting a solution should be possible.

    EDIT: Although I don't actually know what your question is.
    Last edited: Apr 18, 2009
  4. Apr 18, 2009 #3
    You didn't even say what the problem is.
  5. Apr 18, 2009 #4
    *How long until the species have the same mass? Sorry.
  6. Apr 18, 2009 #5
    Okay so you know the equations by which they grow for each of them, and then you set them equal to each other and solve for t.
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