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Math Help - What is the missing number?

  1. #1
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    What is the missing number?

    What is the number that goes where the question mark is?

    { 1, 6, 3, 7, ?, 12, 9, 14 }

    possible numbers: 4, 7, 8, 10, 11, 13
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  2. #2
    Like a stone-audioslave ADARSH's Avatar
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    ANs is 8
    Sum of 1st and last term = 15

    Sum of 2nd and second last = 15

    7+? = 15

    ? = 8

    Game Over XXX
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  3. #3
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    Quote Originally Posted by jerick View Post
    what is the number that goes where the question mark is?
    { 1, 6, 3, 7, ?, 12, 9, 14 }
    possible numbers: 4, 7, 8, 10, 11, 13
    hint:
    6 - 1 = 5, 14 - 9 = 5
    6 - 3 = 3, 12 - 9 = 3
    7 - 3 = 4, 11 - 7 = 4
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  4. #4
    Like a stone-audioslave ADARSH's Avatar
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    hint:
    6 - 1 = 5, 14 - 9 = 5
    6 - 3 = 3, 12 - 9 = 3
    7 - 3 = 4, 11 - 7 = 4
    I guess you want to say 11 as your answer

    If 11 is taken as answer than

    1......(add5)......6......(substract3)......3..... (add 4).....7.......(add4)....11....(add1)....12....(su bstract3).....9.....(add5)......14

    This doesn't look correct

    How do you explain that (add1) in b/w 11 and 12?

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    Sorry if I am wrong in guessing from your hint.
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  5. #5
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    Hi Adarsh, Wilmer...

    Wilmer, shouldn't you have said

    7-3=12-?

    a bit of a symptom of Adarsh's method though
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  6. #6
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    Well, who cares...EIGHT is the answer

    Apologies; not enough coffee...
    Last edited by Wilmer; April 30th 2010 at 11:52 AM. Reason: Correct my error
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  7. #7
    Like a stone-audioslave ADARSH's Avatar
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    Well, who cares...11 is the answer
    Well I do care and I am sure OP also does...... and if I am not wrong we all in MHF do care to do correct things by currect method.

    And No its still 8.
    ---
    Sorry for being rude but that statement doesn't suit you.
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  8. #8
    Super Member Bacterius's Avatar
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    I say all possibilities suit the pattern, because I found that the pattern rule was that "they are all numbers".

    Jokin', the answer should be 8, if the OP could now confirm if the puzzle has been solved ?
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  9. #9
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    Yep, the answer is 8.


    Or: (x-1)(x-6)(x-3)(x-7)(x-?)(x-12)(x-9)(x-14)=0
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  10. #10
    MHF Contributor Swlabr's Avatar
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    Quote Originally Posted by Archie Meade View Post
    Hi Adarsh, Wilmer...

    Wilmer, shouldn't you have said

    7-3=12-?

    a bit of a symptom of Adarsh's method though
    I thought Wilmer's hint was quite neat. I was, as he said, a hint, and so hinted towards Adarsh's solution. Small typo, but that is beside the point.


    Quote Originally Posted by ADARSH View Post
    Well I do care and I am sure OP also does...... and if I am not wrong we all in MHF do care to do correct things by currect method.

    And No its still 8.
    ---
    Sorry for being rude but that statement doesn't suit you.
    I propose that the number is not 8, instead it is 426/35. There is a perfectly logical sequence which goes 1, 6, 3, 7, 426/35, 12, 9, 14... I challenge you to find it.

    (My point is that no, it doesn't matter!)
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