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Posers and Puzzles

Posers and Puzzles

  1. Standard member wolfgang59
    Infidel
    20 Sep '09 10:48 / 1 edit
    Which of these numbers is the odd one out?
    331
    3,331
    33,331
    333,331
    3,333,331
    33,333,331
    333,333,331

    and why?
  2. 20 Sep '09 11:09 / 3 edits
    Originally posted by wolfgang59
    Which of these numbers is the odd one out?
    331
    3,331
    33,331
    333,331
    3,333,331
    33,333,331
    333,333,331

    and why?
    Guessing: Has it something to do with
    primes
    ?
  3. 20 Sep '09 11:14
    333,333,331 is divisable by 17. The others are prime numbers ... I hope.
  4. Standard member wolfgang59
    Infidel
    20 Sep '09 13:50
    Yep! Pretty amazing .... only just come across this phenomenon.