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Homework Help: Proof of Divisibility of 8 rule

  1. Nov 26, 2007 #1
    1. The problem statement, all variables and given/known data
    Let n be a natural number. If the number formed by the last three digits of n is divisible by 8, then n is divisible by 8.


    2. Relevant equations
    Natural numbers are the set of {1,2,3,4,5,6,...}


    3. The attempt at a solution
    I believe we should use a direct proof to prove this conditional statement. Thus we will assume that n is a natural number and the number formed by the last three digits of n is divisible by 8. We will prove that n is divisible by 8.
    I don't know where to go from here. Please help!
     
  2. jcsd
  3. Nov 27, 2007 #2

    Ben Niehoff

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    Science Advisor
    Gold Member

    Hint: What is the lowest power of 10 that is divisible by 8?
     
  4. Nov 27, 2007 #3
    Reply to Hint

    Okay so 1000 is the lowest power of 10 that is divisible by 8. How do I use that?
     
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