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Lower and Upper bound proof in R

  1. Mar 7, 2013 #1
    I am getting lost in the proof in the 5th line when it says there are 10 numbers that have the same kth digit as x. Why 10? I don't understand where this number is coming from and it doesn't seem arbitrary.

    0306132311a.jpg
    the rest of the proof
    http://i603.photobucket.com/albums/tt113/KtmPayton/0306132314.jpg
     
  2. jcsd
  3. Mar 7, 2013 #2

    pwsnafu

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    Science Advisor

    From the fact that the decimal expression is in base 10.
    Walk through the proof with a specific example.
     
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