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Homework Help: Help! More counting problems

  1. Jul 8, 2006 #1
    Hi,

    I've done more questions. Hopefully the wordings on these word problems aren't vague.

    Could someone take a look? I'm not sure if I've thought about the problem the right way. :smile:

    Thanks v. much in advance.
     

    Attached Files:

  2. jcsd
  3. Jul 8, 2006 #2

    arildno

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    Dearly Missed

    Try to learn LATEX, don't use the doc-format
     
  4. Jul 9, 2006 #3

    0rthodontist

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    In the first one, the confusion is that you only need 5 letters to define a 9 letter palindrome. If you know the first 5 letters are ABCDE, then you know the last 4 letters are DCBA. So you only get to choose the first 5 letters, so that's how many possibilities there are.

    In the second one, count the number of bridges available at each step. First step: 3 bridges. Second step: 4 bridges. Third step (going back): three bridges because you can't use the one you came on. Fourth step: 2 bridges
     
    Last edited: Jul 9, 2006
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