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What comes next?5, 3, 42, 86, 15, 24, 25, 168, 2, 4, ?

  1. May 26, 2005 #1
    What comes next?

    5, 3, 42, 86, 15, 24, 25, 168, 2, 4, ?
     
  2. jcsd
  3. May 26, 2005 #2
    6 could it be
     
  4. May 26, 2005 #3
    Nope, not 6.

    Larger.
     
  5. May 26, 2005 #4
    Answer: 35
    - - - - - - - -
     
  6. May 26, 2005 #5
    Good job, Bicycle Tree! You're good.
     
  7. May 26, 2005 #6

    James R

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    Is anybody going to explain?
     
  8. May 26, 2005 #7
    Ok. The sequence is a palindrome.
     
  9. May 27, 2005 #8
    In that case, 3 would serve as well (until moo added the extra condition).
     
  10. May 27, 2005 #9
    what palindrome suppose to mean ?
     
  11. May 27, 2005 #10
    Man... darn... I saw it right after I looked at BicycleTree's response... Oh well.

    Palindrome is the same backwards as it is forwards... they just have the commas in strange places.
     
  12. May 27, 2005 #11

    NateTG

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    But there's an infinite number of options that makes it a palindrome. For example:
    42861524251682435
    142861524251682435
    1142861524251682435
    11142861524251682435
    111142861524251682435
    1111142861524251682435

    And so on.
     
  13. May 28, 2005 #12
    If you take the 4 (from the 24) as the middle of the sequence, then the numbers before and after are the same. So directly before/after the 4 there is a 2 then a 5 then a 1 then a 6 and then an 8 and so on. I would have thought that the answer could have also been:
    '3, 5' (but then there would be more commas on the right of the 4)

    PS
     
    Last edited: May 28, 2005
  14. May 28, 2005 #13
    so the trick is just right at the comma. i got it. thx all
     
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