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Difficult equation

  1. Sep 10, 2011 #1
    I'm having some problems with this equation and would like some help to get further to the solution.


    1. The problem statement, all variables and given/known data


    A box of chocolate candybars contains 9/10 good candybars.
    When someone has taken only of the good candybars
    there are 8/10 of the good candybars left in the box.

    How much is then left?


    3. The attempt at a solution


    x = number of candybars in the box

    y = number of good candybars in the box


    [itex] y=\frac{9}{10}\cdot x[/itex]
     
  2. jcsd
  3. Sep 10, 2011 #2

    NascentOxygen

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    Staff: Mentor

    Is there a word missing?

    "When someone has taken only ??? of ..."

    Does 9/10 mean 90% are good?
     
  4. Sep 10, 2011 #3
    no






    yes
     
  5. Sep 10, 2011 #4

    NascentOxygen

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    x = initial number of candybars in the box

    y = initial number of good candybars in the box

    y=0.9 x

    now, remove g good candybars
    and this leaves you with x-g candybars in the box

    of these, you know that y-g are good.

    continue
     
  6. Sep 10, 2011 #5
    I don't understand
     
  7. Sep 10, 2011 #6

    gb7nash

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    Homework Helper

    This isn't a sentence. Either there's a word missing or the problem's copied wrong (or miswritten).
     
  8. Sep 10, 2011 #7
    Mistranslated from a european language. Could you explain why and write how you think the correct sentence should be written
     
  9. Sep 10, 2011 #8

    gb7nash

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    There's no way to tell. One guess would be:

    When someone has taken one of the good candybars there are 8/10 of the good candybars left in the box.

    Another could be:

    When someone has taken only 10 of the good candybars there are 8/10 of the good candybars left in the box.

    These are just guesses though. You need to get a proper translation.
     
  10. Sep 10, 2011 #9

    uart

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    If there are no missing words then I think "only" is a mistranslation of "one". Which makes it a pretty easy question. :smile:
     
  11. Sep 11, 2011 #10

    NascentOxygen

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    First, apologies if the response to your writing seems to have been a bit abrupt. Don't let that put you off posting more questions. I guess that English is not your first language.

    By itself, the sentence isn't, in fact, wrong; a better description word would be that today it seems "awkward". It is unusual in contemporary writing, but would fit perfectly into last century's style of English writing.

    Instead of "taken only of the" we might today write "eaten some".

    Is there more detail to the question?

    I am anticipating this to be an algebraic puzzle demanding an integer answer.
     
    Last edited: Sep 11, 2011
  12. Sep 12, 2011 #11

    HallsofIvy

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    This question was posted on another board with the person taking one of the good candy bars as gb7nash suggested. However, the answer comes out in fractional candy bars which doesn't seem reasonable.
     
  13. Sep 12, 2011 #12

    NascentOxygen

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    Well I didn't like this question right from the start, anyway.

    Whoever heard of a candybar that isn't good?! :smile:
     
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