5+5+5-5+5+5-5+5*0=

Discussion in 'Community Discussion' started by Mac'nCheese, Nov 9, 2011.

?

5 + 5 + 5 - 5 + 5 + 5 - 5 + 5 x 0 = ?

  1. 20

    4.9%
  2. 0

    29.2%
  3. 40

    0.8%
  4. 15

    65.2%
  1. Mac'nCheese macrumors 68030

    Mac'nCheese

    Joined:
    Feb 9, 2010
    #1
    Its on facebook....

    What does 5+5+5-5+5+5-5+5*0=

    20, 0, 40 or 15?
     
  2. szolr macrumors 6502

    Joined:
    Jul 27, 2011
    Location:
    London, UK
    #2
    Er... 15? ;)
     
  3. AdrianK macrumors 68020

    Joined:
    Feb 19, 2011
    #3
    Did anyone else read that as all addition the first time they saw it? @_@

    Anyway, I'd assume 15.
     
  4. GoCubsGo macrumors Nehalem

    GoCubsGo

    Joined:
    Feb 19, 2005
    #4
    15 I think. Most will say 0 because of the multiplication by zero but I think it goes:
    5+5+5-5+5+5-5+(5*0)= and that is 15.
     
  5. szolr macrumors 6502

    Joined:
    Jul 27, 2011
    Location:
    London, UK
    #5
    BIDMAS-standard maths principles lol
     
  6. ericrwalker macrumors 68030

    ericrwalker

    Joined:
    Oct 8, 2008
    Location:
    Albany, NY
  7. iJohnHenry macrumors P6

    iJohnHenry

    Joined:
    Mar 22, 2008
    Location:
    On tenterhooks
    #10
    "What do you want it to equal?" - Sleazy Accountant
     
  8. cantthinkofone macrumors 65816

    cantthinkofone

    Joined:
    Jul 25, 2004
    Location:
    Missouri, USA
    #11
    Hate order of operations, gets me every time.
     
  9. jav6454 macrumors P6

    jav6454

    Joined:
    Nov 14, 2007
    Location:
    1 Geostationary Tower Plaza
  10. eawmp1 macrumors 601

    eawmp1

    Joined:
    Feb 19, 2008
    Location:
    FL
    #13
    I knew the meaning, but now I see the math behind it. Cool. ;)
     
  11. puma1552, Nov 9, 2011
    Last edited: Nov 9, 2011

    puma1552 macrumors 601

    Joined:
    Nov 20, 2008
    #14
    -5

    5+5+5-5+5+5-5+5*0

    PMDAS order of operations, Parentheses, Multiplication, Division, Addition, Subtraction

    Grouping terms according to order of operations reduces to

    (5+5+5)-(5+5+5)-[5+(5*0)]
    =15-15-5+0
    =-5

    Probably wrong, and probably another one of these useless puzzles where everyone is wrong usually on accounta the way it's entered into the computer in type format and not common sense format...pretty sure the last time one of these came up the guy did a bogus job of entering it into the computer

    Or, alternatively,

    (5+5)+(5-5)+(5+5)-5+0
    =15

    But that is arbitrary term grouping where you are selecting which operation signs to put in or outside of the parentheses, which is no good.
     
  12. wpotere Guest

    Joined:
    Oct 7, 2010
    #15
    Dang it... It is 15 but I have already voted. :(
     
  13. iJohnHenry macrumors P6

    iJohnHenry

    Joined:
    Mar 22, 2008
    Location:
    On tenterhooks
    #16
    And now you know why macaroni & cheese made it a public poll. :p
     
  14. Rodimus Prime macrumors G4

    Rodimus Prime

    Joined:
    Oct 9, 2006
    #17
    Damn delexia after I put my vote in I saw I was reading one of the 5 twice and was getting it crossed. It should be 15.
     
  15. rdowns macrumors Penryn

    rdowns

    Joined:
    Jul 11, 2003
  16. eawmp1 macrumors 601

    eawmp1

    Joined:
    Feb 19, 2008
    Location:
    FL
    #19
    Wrong, because YOU put in parentheses.
    And multiplication=division and addition=subtraction...neither is done first. You do these from left to right.
     
  17. dukebound85 macrumors P6

    dukebound85

    Joined:
    Jul 17, 2005
    Location:
    5045 feet above sea level
    #20
    That is incorrect. You do not put () in at all in this case as () fundamentally changes the oder of operations. Addition and Subtraction are the same. Neither takes precedence over the other. Same with Mult and Division. As such, you merely go Left to Right with those operations

    The reason addition and subtraction are the same is because adding -5 is the same as subtracting 5 for instance. Same logic for mult and division
     
  18. mscriv macrumors 601

    mscriv

    Joined:
    Aug 14, 2008
    Location:
    Dallas, Texas
    #21
    I voted 15 because that makes sense using PEMDAS and working left to right. Does left to right come into play with calculations? I don't know, grade school math was so long ago. However, puma1552's post below makes sense as well depending upon how you apply PEMDAS if it's not left to right. I don't remember the rule.


     
  19. puma1552 macrumors 601

    Joined:
    Nov 20, 2008
    #22
    Thanks duke, been a long time...had I seen it scribbled on paper I would've went left to right, but since it's on the computer you always assume it's a setup/trick and not as easy as it would otherwise look.
     
  20. waloshin macrumors 68040

    waloshin

    Joined:
    Oct 9, 2008
  21. eawmp1, Nov 9, 2011
    Last edited by a moderator: Nov 9, 2011

    eawmp1 macrumors 601

    eawmp1

    Joined:
    Feb 19, 2008
    Location:
    FL
    #24
    That's why the LAST 5 zeroes out, not everything before the "+"
     
  22. iStudentUK macrumors 65816

    iStudentUK

    Joined:
    Mar 8, 2009
    Location:
    London

Share This Page