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Homework Help: Help : sequence problem

  1. Dec 9, 2004 #1
    help plz: sequence problem

    how do you solve this question plz help!!! thx!!!

    A current population is 2 000 000 and it increases 7% annualy. However each year a certain number of people die (this amount is constant for every year). How many people die each year if the population is to become 2 500 000 in 8 years?

    plz list steps thx!!!
  2. jcsd
  3. Dec 9, 2004 #2
    let a = 2 000 000 (the starting number)
    r = 1.07 (the percentage, 100% + 7%)
    n = 8 (because - you want to find out after 8 years)

    using the Geometric Sequence formula...

    t_n = ar^{n-1}

    SHould be pretty simple.
  4. Dec 9, 2004 #3


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    Almost. After you calculate the growth with no deaths (futbol's post), subtract 2,500,000. That tells you how many died over the 8 year period. It's a constant rate, so you need the average number of deaths per year.
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