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Solve this equation > 48÷2(9+3) = ?

11112141617108

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    John259John259 Posts: 28,588
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    A bit more Googling suggests that the concept of juxtaposition having a higher priority than a multiplication sign is far from being universally accepted.
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    jjnejjne Posts: 6,580
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    John259 wrote: »
    A bit more Googling suggest that the concept of juxtaposition having a higher priority than a multiplication sign is far from being universally accepted.

    I find it interesting that I do not think the juxtaposition should take precedence, but that my subconscious calculation of what was in front of me said otherwise.
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    irishguyirishguy Posts: 22,172
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    Well I'm no mathematician, unlike others on the thread :o but for the number to be less than one, the amount it's less by has to be quantifiable and if the 9 is infinite then the difference between the 0.99999999999999999...... and 1 is incalculable.

    Now someone who knows what they're talking about might explain it properly :D

    Actually that does make sense. Maybe thats what the wikipedia page was saying but my denseness to maths rendered the whole thing incomprehensible!
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    jrajra Posts: 48,325
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    So, if you use juxtapostion rules as stated above the answer is 2, but if you generally work left to right (after brackets) the answer is 288?

    In other words, either answer is technically correct.
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    Biffo the BearBiffo the Bear Posts: 25,861
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    jra wrote: »
    So, if you use juxtapostion rules as stated above the answer is 2, but if you generally work left to right (after brackets) the answer is 288?

    In other words, either answer is technically correct.

    Not really - 2 is the only correct answer because the juxtaposition rule applies.

    If it was 2 x (3+9) then it would be 288 and only 288.
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    Super FrogSuper Frog Posts: 11,480
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    I got a weird answer, lots of strange numbers and symbols. When I turned my page sideways it spelled out "STOP F*CKING MAKING POLLS".

    Bizarre.
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    Doctor_WibbleDoctor_Wibble Posts: 26,580
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    John259 wrote: »
    No. In maths expressions the "context" is irrelevant. The symbols and the rules of computation are unambiguous.
    If encountering such a thing in real life, the proper response is one (or all) of:
    a) you're fired
    b) WTF is this meant to mean
    c) 0/10
    though I would still (in the absence of clarification) take '2' as the answer.

    Without context the expression in the OP is one of frustration, not mathematics.
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    jjnejjne Posts: 6,580
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    irishguy wrote: »
    Actually that does make sense. Maybe thats what the wikipedia page was saying but my denseness to maths rendered the whole thing incomprehensible!

    Another way to look at it...

    2 - 0.99999............ = 1.0000000000...........

    Is 1.00000......... = 1?

    The difference between 1 and 1.000000.... is the same as the difference between 0.999999...... and 1, but the human mind has an easier time rationalising 1.0000000.......
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    [Deleted User][Deleted User] Posts: 735
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    John259 wrote: »
    A bit more Googling suggests that the concept of juxtaposition having a higher priority than a multiplication sign is far from being universally accepted.

    Just accept you were wrong mate :D

    Was a fun discussion though... not many got it right.
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    John259John259 Posts: 28,588
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    jra wrote: »
    So, if you use juxtapostion rules as stated above the answer is 2, but if you generally work left to right (after brackets) the answer is 288?
    That's what it all hinges on.

    It would seem that hardly any maths teachers, lecturers or text books mention juxtaposition so it looks like it's a huge way from being universally accepted.
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    lemonbunlemonbun Posts: 5,371
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    Not really - 2 is the only correct answer because the juxtaposition rule applies.

    If it was 2 x (3+9) then it would be 288 and only 288.

    That is the problem. People are assuming that 2(3+9) is the same as 2 times (3 + 9) in any equation. It is not and has never been.
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    John259John259 Posts: 28,588
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    FWIW that article says that juxtaposition is exactly the same as a multiplication sign, implying that they have exactly the same priority.
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    irishguyirishguy Posts: 22,172
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    jjne wrote: »
    Another way to look at it...

    2 - 0.99999............ = 1.0000000000...........

    Is 1.00000......... = 1?

    The difference between 1 and 1.000000.... is the same as the difference between 0.999999...... and 1, but the human mind has an easier time rationalising 1.0000000.......

    Yeah, I can see that. Thanks for somewhat renewing my faith in maths.
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    neelianeelia Posts: 24,186
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    Well I'm no mathematician, unlike others on the thread :o but for the number to be less than one, the amount it's less by has to be quantifiable and if the 9 is infinite then the difference between the 0.99999999999999999...... and 1 is incalculable.

    Now someone who knows what they're talking about might explain it properly :D

    Having failed to start a ruck between Pure Mathematicians and the Applied sort, I'll be nice and say you may have missed your calling as that is more or less it :)

    As you tend to infinity with your number of 9s (1 - 0.999999999) tends to 0. For every wee totty number "wtn" you can think of there is a number n such that (1- 0.99999999 repeated n times ) is less than wtn :)
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    jjnejjne Posts: 6,580
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    John259 wrote: »
    That's what it all hinges on.

    It would seem that hardly any maths teachers, lecturers or text books mention juxtaposition so it looks like it's a huge way from being universally accepted.

    It is a strange one.

    My mathematics brain is saying that juxtaposition takes precedence.

    My comp-sci brain is saying "bollocks".

    The rest of my head is left wondering why these two haven't ripped each other to pieces over this issue in the last 37 years.
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    [Deleted User][Deleted User] Posts: 326
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    Answer = 288, if interpreting it this way:

    48
    --- (9+3)
    2

    = 288

    However, it could also be interpreted in this manner:

    48
    ----
    2(9+3)

    = 2

    I believe, however, the latter should be expressed as such if it was intended to avoid ambiguity: 48/(2(9+3)).

    Without the clarifying brackets it would make most sense in my mind to interpret it in the first way. That's obviously not the consensus among everyone.

    In conclusion, no serious mathematician would touch a problem like this without additional clarity. The way it was written in the original post is intended to be ambiguous and cause exactly these type of arguments. If you passionately believe one side or the other, and brand others as "wrong," then you're just failing to accept the question itself is flawed and letting your ego cloud your ability to rationally see how both evaluations could theoretically be "right" as it stands. It's time to accept the question itself is the problem here. :)

    Cheers.
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    John259John259 Posts: 28,588
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    jjne wrote: »
    The rest of my head is left wondering why these two haven't ripped each other to pieces over this issue in the last 37 years.
    Probably because anyone competent in each field would write such things unambiguously in their own area's notation.
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    lemonbunlemonbun Posts: 5,371
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    John259 wrote: »
    That's what it all hinges on.

    It would seem that hardly any maths teachers, lecturers or text books mention juxtaposition so it looks like it's a huge way from being universally accepted.
    It's the simple fact that 2 * (x + y) is not the same as 2 (x + y) in an expression/equation.
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    lozloz Posts: 4,720
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    In conclusion, no serious mathematician would touch a problem like this without additional clarity. The way it was written in the original post is intended to be ambiguous and cause exactly these type of arguments. If you passionately believe one side or the other, and brand others as "wrong," then you're just failing to accept the question itself is flawed and letting your ego cloud your ability to rationally see how both evaluations could theoretically be "right" as it stands. It's time to accept the question itself is the problem here. :)

    I was just about to post that the only conclusion I can draw so far is that the problem is ambiguous and can be interpreted either way, and no one has come up with any cast iron rule that proves it one way or the other.

    So I agree with you.
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    [Deleted User][Deleted User] Posts: 735
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    John259 wrote: »
    FWIW that article says that juxtaposition is exactly the same as a multiplication sign, implying that they have exactly the same priority.


    "juxtaposition indicates multiplication of variables"

    Therefore 2(12) should be replaced with 24...
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    John259John259 Posts: 28,588
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    It's time to accept the question itself is the problem here.
    That is very true, but it raises some doubt about whether seemingly totally valid expressions such as a/bc should be evaluated as (a/b)*c or as a/(b*c).
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    John259John259 Posts: 28,588
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    "juxtaposition indicates multiplication of variables"
    Sure, but that says nothing about it taking precedence over division.
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    MoonyMoony Posts: 15,093
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    Microsoft excel gives 288
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    neelianeelia Posts: 24,186
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    jjne wrote: »
    It is a strange one.

    My mathematics brain is saying that juxtaposition takes precedence.

    My comp-sci brain is saying "bollocks".

    The rest of my head is left wondering why these two haven't ripped each other to pieces over this issue in the last 37 years.

    Because your Mathematics brain knows that it has an unfair advantage and hasn't pressed it :p
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