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Math Help - Word Problem Help?!

  1. #1
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    Word Problem Help?!

    This is from Biology:

    Bacteria reproduce asexually (split in 2) at a rate of 20 minutes. How many DECENDANTS do you have at 20 minutes? 40 minutes? 60 minutes? Two hours? Three hours? 24 hours?

    Also the formula to figure this out would be extremely helpful! Thank you!
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  2. #2
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    Re: Word Problem Help?!

    Quote Originally Posted by Theboro View Post
    Bacteria reproduce asexually (split in 2) at a rate of 20 minutes.
    Rate is the number of something (such as kilometers or splittings) in a unit of time (such as 20 minutes). A rate cannot me measured in minutes.

    Quote Originally Posted by Theboro View Post
    How many DECENDANTS do you have at 20 minutes?
    This depends on how many bacteria you start with and on whether bacteria die.
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  3. #3
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    Re: Word Problem Help?!

    You don't need a formula, you just need to think about what "splits in two" means. If one splits in to two in 20 minutes, then starting with one, you have two in 20 minutes. In another 20 minutes each of those will split into two. How many will there be then? In another 20 minutes, each of those will split into two. How many will that make?

    Having just read emakarov's response, I am assuming that you mean "at a rate of one split every 20 minutes", that you are starting with one, and that none die.
    Last edited by HallsofIvy; October 10th 2012 at 11:14 AM.
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  4. #4
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    Re: Word Problem Help?!

    I got
    20 min=2 cells
    40 min=4 cells
    60 min=8 cells
    2 hours=640 cells
    3 hours=5120 cells
    24 hours=20971520 cells

    is this correct? I feel like it's not.
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  5. #5
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    Re: Word Problem Help?!

    Quote Originally Posted by Theboro View Post
    I got
    20 min=2 cells
    40 min=4 cells
    60 min=8 cells
    2 hours=640 cells
    3 hours=5120 cells
    24 hours=20971520 cells

    is this correct?
    The numbers for 2 and 3 hours are too big by a factor of 10. The number for 24 hours should be about 2 times bigger.
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