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Thread: Weird puzzle

  1. #1
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    Weird puzzle

    Found this:

    12-7*6+19-14=11
    Add brackets only (no limit) so above is correct.

    I can't do it...
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  2. #2
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    Re: Weird puzzle

    did you get an answer whether splitting numbers, ala 19 -> (1)(9), was legit?
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  3. #3
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    Re: Weird puzzle

    Could the RHS be 1, ie (1)(1), rather than 11?
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  4. #4
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    Re: Weird puzzle

    I simply don't know...
    The fact that * is used for multiplication in the problem seems to eliminate (1)(9).

    Found this site which "apparently" solved it...but can't join the damn place:

    https://www.chegg.com/homework-help/...laces-q7371809
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  5. #5
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    Re: Weird puzzle

    Quote Originally Posted by DenisB View Post
    I simply don't know...
    The fact that * is used for multiplication in the problem seems to eliminate (1)(9).

    Found this site which "apparently" solved it...but can't join the damn place:

    https://www.chegg.com/homework-help/...laces-q7371809
    They've heard of you, huh?

    -Dan
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  6. #6
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    Re: Weird puzzle

    Well, why don't you guys try and join....!!
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  7. #7
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    Re: Weird puzzle

    It seems you have to pay! Not doing that.
    Last edited by Debsta; Apr 17th 2019 at 10:38 PM.
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  8. #8
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    Re: Weird puzzle

    Quote Originally Posted by DenisB View Post
    Found this:

    12-7*6+19-14=11
    Add brackets only (no limit) so above is correct.

    I can't do it...
    There are $14$ ways to parenthesize the expression $12-7*6+19-14$

    If none of them give $11$ as the answer then this is a trick question
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  9. #9
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    Re: Weird puzzle

    Quote Originally Posted by Idea View Post
    There are 14 ways to parenthesize the expression 12−7∗6+19−14
    Including nested parenthesizing?
    Last edited by DenisB; Apr 18th 2019 at 10:58 AM.
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  10. #10
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    Re: Weird puzzle

    these are the 14 ways in which the expression can be calculated

    $\displaystyle 12-(7*(6+(19-14))),$
    $\displaystyle 12-(7*((6+19)-14)),$
    $\displaystyle 12-((7*6)+(19-14)),$
    $\displaystyle 12-((7*(6+19))-14),$
    $\displaystyle 12-(((7*6)+19)-14),$
    $\displaystyle (12-7)*(6+(19-14)),$
    $\displaystyle (12-7)*((6+19)-14),$
    $\displaystyle (12-(7*6))+(19-14),$
    $\displaystyle ((12-7)*6)+(19-14),$
    $\displaystyle (12-(7*(6+19)))-14,$
    $\displaystyle (12-((7*6)+19))-14,$
    $\displaystyle ((12-7)*(6+19))-14,$
    $\displaystyle ((12-(7*6))+19)-14,$
    $\displaystyle (((12-7)*6)+19)-14$

    14 is the $\displaystyle 4^{th}$ Catalan number
    (there are 4 operations in the given expression and 5 operands)

    and the 14 possible values

    $\displaystyle \{-65,-65,-35,-149,-35,55,55,-25,35,-177,-63,111,-25,35\}$

    11 does not appear in the list (but there is a 111)
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  11. #11
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    Re: Weird puzzle

    Quote Originally Posted by Idea View Post
    11 does not appear in the list (but there is a 111)
    Thanks...I at least got the "111"!!
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  12. #12
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    Re: Weird puzzle

    Have you tried it where you can split the 2-digit numbers with a left or right bracket? Or where the RHS is (1)(1) = 1 rather than 11.
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