Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

6÷2(1+2)=?

Options
  • 28-04-2011 3:11pm
    #1
    Registered Users Posts: 153 ✭✭


    This is a pretty big question on facebook at the mo... What's the answer? I say 1.

    (The option is 1 or 9)

    It was asked by this fella
    http://www.facebook.com/home.php#!/m...s?sk=questions

    Just click "asked" at the top right and you should see it.


«1345

Comments

  • Registered Users Posts: 3,863 ✭✭✭mikhail


    It's 1. BOMDAS says you do the bit in brackets first (leaving 6/2.3), then the multiplication (6/6) and finally the division gives 1. To get nine, you have to do the division before the multiplication, which is wrong.


  • Registered Users Posts: 1,424 ✭✭✭Ciano35


    It's 1, because of bomdas as said above.


  • Registered Users Posts: 5,083 ✭✭✭RoundTower


    if it is 1, it definitely isn't for that reason

    was this moved to this forum?


  • Closed Accounts Posts: 1,479 ✭✭✭William Powell


    It has to be ONE.

    If you were to write it out differently something like this

    6
    = ?
    2(1+2)

    then it becomes more obvious that the
    bit is like a brackets in itself so you do everything underneath it first and the division last.

    OK not a great explaination but the best I can manage.


  • Registered Users Posts: 1,025 ✭✭✭muboop1


    The answer is 9...

    BOMDAS is a rough held rule,

    It kinda works in groupings almost.

    (B)(O)(MD)(AS)

    Multiplication and division are more of a pair. You solve which ever if first.

    Actually, found it here: http://en.wikipedia.org/wiki/Order_of_operations
    Mnemonics are often used to help students remember the rules, but the rules taught by the use of acronyms can be misleading. In Canada the acronym BEDMAS is common. It stands for Brackets, Exponents, Division, Multiplication, Addition, Subtraction. In other English speaking countries, Brackets may be called Parentheses, or symbols of inclusion and Exponentiation may be called either Indices, Powers or Orders, and since multiplication and division are of equal precedence, M and D are often interchanged, leading to such acronyms as BIMDAS, BODMAS, BOMDAS, BERDMAS, PERDMAS, PEMDAS, PEDMAS and BPODMAS.


  • Advertisement
  • Closed Accounts Posts: 2,630 ✭✭✭folan


    jblack wrote: »
    6/2(3/1) = 18/2 = 9
    what you have done is (6/2)(1+2), not 6/2(1+2)


  • Moderators, Category Moderators, Politics Moderators, Recreation & Hobbies Moderators, Society & Culture Moderators Posts: 81,309 CMod ✭✭✭✭coffee_cake


    It's 1


  • Registered Users Posts: 490 ✭✭Chefburns


    No doubt about it, its 1.


  • Registered Users Posts: 476 ✭✭jblack


    see it now..


  • Posts: 0 ✭✭✭✭ [Deleted User]


    Bemdas

    Brackets
    Exponents
    Multiplication
    Division
    Addition
    Subtraction

    So it's 1+2 =3

    Next is the multiplication of 2(3)= 6

    Finally division 6/6=1


  • Advertisement
  • Moderators, Business & Finance Moderators Posts: 4,991 Mod ✭✭✭✭Shane732


    Is there a link to the question??

    I'd like to laugh at people!! :p


  • Registered Users Posts: 2,059 ✭✭✭Screaminmidget


    muboop1 wrote: »
    The answer is 9...

    BOMDAS is a rough held rule,

    It kinda works in groupings almost.

    (B)(O)(MD)(AS)

    Multiplication and division are more of a pair. You solve which ever if first. Same with addition and subtraction.

    You're wrong. Its 1.


  • Registered Users Posts: 3,863 ✭✭✭mikhail


    muboop1 wrote: »
    The answer is 9...

    BOMDAS is a rough held rule,

    It kinda works in groupings almost.

    (B)(O)(MD)(AS)

    Multiplication and division are more of a pair. You solve which ever if first. Same with addition and subtraction.
    I see what you mean, but I don't agree that you first solve whichever appears first. That works fine for addition and subtraction because the answer is the same any way you like.

    In light of what you've said above, I'd like to change my answer to "Kick whoever set the question in the balls."


  • Registered Users Posts: 1,025 ✭✭✭muboop1


    I edited my original answer... please look...proof is there!

    Ill accept your apologies after...


  • Registered Users Posts: 1,025 ✭✭✭muboop1


    Guys think about it... We all agree that brackets come first..

    So, sum is effectively 6/2*3 yeh??

    well...

    that could similarily be written (6/2)*3 or

    6*3
    2 1


  • Registered Users Posts: 68,317 ✭✭✭✭seamus


    mikhail wrote: »
    I see what you mean, but I don't agree that you first solve whichever appears first. That works fine for addition and subtraction because the answer is the same any way you like.
    Actually it would appear that this is the case, learn something new every day.

    Rule of thumb is to convert everything to the same operator to avoid confusion.

    So the above becomes 6 * ½ * (2 + 1)

    Which is a whole lot clearer.


  • Moderators, Business & Finance Moderators Posts: 4,991 Mod ✭✭✭✭Shane732


    48÷2(9+3)=


  • Registered Users Posts: 1,025 ✭✭✭muboop1


    Shane732 wrote: »
    48÷2(9+3)=

    288...

    What sort of game is this?? Your calculator can do it for u! :P


  • Registered Users Posts: 10,514 ✭✭✭✭28064212


    mikhail wrote: »
    It's 1. BOMDAS says you do the bit in brackets first (leaving 6/2.3), then the multiplication (6/6) and finally the division gives 1. To get nine, you have to do the division before the multiplication, which is wrong.
    Multiplication does not come before division. Multiplication and division have exactly equal precedence.

    The problem can be rewritten: 1+2 can be replaced by 3, since that will always be done first, so we have 6 ÷ 2 * 3. Because division and multiplication have the same preference, we have to look at operator associativity. Both are left-associative, meaning they're grouped from the left, so it's (6 ÷ 2) * 3, not 6 ÷ (2 * 3). The answer is most definitely 9.

    And to anyone who still thinks the answer is 1 after that: What's 6 - 2 + 3? Should it be 6 - (2 + 3) = 1 or (6 - 2) + 3 = 7?

    Boardsie Enhancement Suite - a browser extension to make using Boards on desktop a better experience (includes full-width display, keyboard shortcuts, dark mode, and more). Now available through your browser's extension store.

    Firefox: https://addons.mozilla.org/addon/boardsie-enhancement-suite/

    Chrome/Edge/Opera: https://chromewebstore.google.com/detail/boardsie-enhancement-suit/bbgnmnfagihoohjkofdnofcfmkpdmmce



  • Closed Accounts Posts: 1,479 ✭✭✭William Powell


    Oh dear someone is missing the point of the brackets :rolleyes:


  • Advertisement
  • Moderators, Business & Finance Moderators Posts: 4,991 Mod ✭✭✭✭Shane732


    It's poor notation.

    The standard is that multiplication and division have same precedence, and are done left to right.

    A lack of parentheses.

    (6/2)(1+2) =


  • Moderators, Business & Finance Moderators Posts: 4,991 Mod ✭✭✭✭Shane732


    muboop1 wrote: »
    288...

    What sort of game is this?? Your calculator can do it for u! :P

    You'd be amazed at the amount of people who say 2 is the answer to 48÷2(9+3)


  • Closed Accounts Posts: 1,307 ✭✭✭stephendevlin


    Where's Einstein when ya need him .... :D


  • Registered Users Posts: 10,514 ✭✭✭✭28064212


    seamus wrote: »
    Actually it would appear that this is the case, learn something new every day.

    Rule of thumb is to convert everything to the same operator to avoid confusion.

    So the above becomes 6 * ½ * (2 + 1)

    Which is a whole lot clearer.
    Changing it to the same operator doesn't really clear it up. Is it 6 * ½ * (2 + 1) or should it be 6 * 1/(2 * (2 + 1))? You don't know whether you should get the reciprocal of 2 or the reciprocal of 2 * (2 + 1)
    Oh dear someone is missing the point of the brackets :rolleyes:
    Is that aimed at me? The rules of precedence and associativity are there so that brackets aren't needed all over the place. Precedence isn't enough to separate the OP's question, so you have to look at the associativity rules

    Boardsie Enhancement Suite - a browser extension to make using Boards on desktop a better experience (includes full-width display, keyboard shortcuts, dark mode, and more). Now available through your browser's extension store.

    Firefox: https://addons.mozilla.org/addon/boardsie-enhancement-suite/

    Chrome/Edge/Opera: https://chromewebstore.google.com/detail/boardsie-enhancement-suit/bbgnmnfagihoohjkofdnofcfmkpdmmce



  • Closed Accounts Posts: 1,307 ✭✭✭stephendevlin


    6/2(1+2)=3(1+2)=9


  • Closed Accounts Posts: 1,479 ✭✭✭William Powell


    28064212 wrote: »
    Changing it to the same operator doesn't really clear it up. Is it 6 * ½ * (2 + 1) or should it be 6 * 1/(2 * (2 + 1))? You don't know whether you should get the reciprocal of 2 or the reciprocal of 2 * (2 + 1)


    Is that aimed at me? The rules of precedence and associativity are there so that brackets aren't needed all over the place. Precedence isn't enough to separate the OP's question, so you have to look at the associativity rules

    So you are saying 6÷2(1+2)=? is the same as 6÷2x(1+2)=?

    thats why :rolleyes:


  • Registered Users Posts: 113 ✭✭Chemistry Ftw


    Shane732 wrote: »
    You'd be amazed at the amount of people who say 2 is the answer to 48÷2(9+3)
    The answer IS 2!!! :P


  • Registered Users Posts: 901 ✭✭✭EL_Loco


    I whacked this into excel:

    =6/2*(1+2)

    it says 9.

    personally I was thinking 1, because the 2(2+1) parts looks "unresolved" or something, as in, you should get it to it's conclusion first. then do the division.

    My world is rocked. I need to lie down.


  • Advertisement
  • Registered Users Posts: 10,514 ✭✭✭✭28064212


    So you are saying 6÷2(1+2)=? is the same as 6÷2x(1+2)=?

    thats why :rolleyes:
    What? That's not something I've specifically stated, it's something universally understood. What on earth do you think it means? What do you think is the difference between 2(1+2) and 2x(1+2)?
    The answer IS 2!!! :P
    It's really not. Multiplication and division have the same precedence and are both left-associative, that means you read it from the left

    Boardsie Enhancement Suite - a browser extension to make using Boards on desktop a better experience (includes full-width display, keyboard shortcuts, dark mode, and more). Now available through your browser's extension store.

    Firefox: https://addons.mozilla.org/addon/boardsie-enhancement-suite/

    Chrome/Edge/Opera: https://chromewebstore.google.com/detail/boardsie-enhancement-suit/bbgnmnfagihoohjkofdnofcfmkpdmmce



This discussion has been closed.
Advertisement