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Thread: Controversial Math Problem

  1. #1 Controversial Math Problem 
    Forum Freshman whoisjohngalt's Avatar
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    62(1+2)=?


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  3. #2  
    Veracity Vigilante inow's Avatar
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    Controversial? No, not really. At least I don't think so.

    Since division and multiplication are equal in priority, you move from left to right when doing the work and it becomes (6 2) * (1 + 2).

    Someone please correct me if this is mistaken.


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  4. #3  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Yeah. There's a reason that most people don't use that symbol, but if you type that in to any calculator, it'll work as inow said. Nothing controversial about it.
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  5. #4  
    Forum Freshman whoisjohngalt's Avatar
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    According to Inow, the answer would be 9. I believe it is 1.

    The way I read the equation would be akin to 6/[(2*1)+(2*2)= 6/6= 1

    I believe the equation is showing 6/(2+4) with the 2 factored out of the denominator to reach the 6/2(1+2)
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  6. #5 Re: Controversial Math Problem 
    . DrRocket's Avatar
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    Quote Originally Posted by whoisjohngalt
    62(1+2)=?
    The basic rule in mathematics is to be clear. The expression 62(1+2) is not clear. To be clear, use parentheses (62)(1+2) or 6(2(1+2)).

    Arguing over what it "should" mean is futile and requires one to be clairvoyant and to use that faculty to divine the intent of the writer.

    This argument is taking place in several forums. It is pointless in each and every one.
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  7. #6  
    Forum Freshman whoisjohngalt's Avatar
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    Yep, and I saw it in another forum. That was a photography forum. I just figured I would see what a math section of the science forum would think. I still say the answer is 1.
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  8. #7  
    Forum Bachelors Degree x(x-y)'s Avatar
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    Hmmmm...

    I just typed 6 divided by 2(1+2) into my calculator and the answer is indeed 1. I suppose it means you do the 2(1+2) first giving 6 and them divide 6 by this equalling 1.

    So, yes, written as that- the answer is 1.
    "Nature doesn't care what we call it, she just does it anyway" - R. Feynman
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  9. #8  
    Your Mama! GiantEvil's Avatar
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    62(1+2)=Math salad.
    I just noticed that my keyboard doesn't have one of those crappy, kindergarten, arithmetic division symbols. Good!
    I was some of the mud that got to sit up and look around.
    Lucky me. Lucky mud.
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  10. #9  
    Forum Radioactive Isotope MagiMaster's Avatar
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    It's the / key. It's the same thing for all intents and purposes.

    I suppose what you get would depend on which calculator or programming language you use, if you use one. (If you're just doing it on paper, it's as DrRocket said and would be considered poorly written.) For most calculators and programming languages (places where you might actually type something like that in) multiplication and division are resolved left to right in the absence of parenthesis and the answer would be 9.

    Try opening your desktop calculator and typing 6/2*(1+2) in that order. Mine gives 9. I know C, C++, Java, Excel and PERL at least would also give 9.
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  11. #10  
    Forum Bachelors Degree x(x-y)'s Avatar
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    Quote Originally Posted by MagiMaster
    It's the / key. It's the same thing for all intents and purposes.

    I suppose what you get would depend on which calculator or programming language you use, if you use one. (If you're just doing it on paper, it's as DrRocket said and would be considered poorly written.) For most calculators and programming languages (places where you might actually type something like that in) multiplication and division are resolved left to right in the absence of parenthesis and the answer would be 9.

    Try opening your desktop calculator and typing 6/2*(1+2) in that order. Mine gives 9. I know C, C++, Java, Excel and PERL at least would also give 9.
    But the question does not ask:



    It asks:



    Which is the same as:



    Thus the answer is 1.
    "Nature doesn't care what we call it, she just does it anyway" - R. Feynman
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  12. #11  
    Comet Dust Collector Moderator
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    Then it should have been written 6/(2(1+2)). If you write it wrong, you will get the wrong answer.
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  13. #12  
    Forum Bachelors Degree x(x-y)'s Avatar
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    Quote Originally Posted by MeteorWayne
    Then it should have been written 6/(2(1+2)). If you write it wrong, you will get the wrong answer.
    Indeed. The question/expression is written in a very unorganised way (as DrRocket stated), there's no disagreement there. But I'm just saying that if you type it like that into a calculator, then you will obtain 1- due to BIDMAS (Brackets, Indices, Division...) most likely.
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  14. #13  
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    Quote Originally Posted by MeteorWayne
    Then it should have been written 6/(2(1+2)). If you write it wrong, you will get the wrong answer.
    It wasn't written wrong. It was written the way it was because it was intended to be ambiguous.
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  15. #14  
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    Well by the basic BODMAS rule I've learnt the answer is 9
    You evaluate the bracket ,division,multiplication
    Quantum
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  16. #15  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Also, you can't actually type 6/2(1+2) into many calculators or programming languages. Mathematica is one of the few I know that'll do multiplication by concatenation like that, but even that gives a 9.

    While brackets do take precedence, the implied multiplication is not a bracket.
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  17. #16  
    Forum Masters Degree thyristor's Avatar
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    Typing "6/2(1+2)" on my TI 84-plus SE I obtain 9.
    373 13231-mbm-13231 373
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