Confusing Math Problem

Discussion in 'Off-Topic Lounge' started by mrchennyken, Sep 4, 2011.

  1. mrchennyken

    mrchennyken Well-Known Member

    Mar 11, 2009
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    I'm getting confused from the wording of this problem, and it's really bothering me. Can anyone help?


    A list showing the results of a race was posted. There were no ties among the runners. One runner realized that 13 more runners had finished after her than had finished before her. She also realized that the total number of runners was 4 times the number of runners who had finished before her. How many runners took part in the race?
     
  2. kohjingyu

    kohjingyu Well-Known Member

    Mar 20, 2009
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    Let runners that finished before her be x.

    Total runners
    = 4x + 1 (her)
    = x + x + 13 + 1

    Therefore, 2x = 14
    x = 7

    Total runners = 4(7) + 1 = 29.

    Is that right?
     
  3. squarezero

    squarezero Moderator
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    #3 squarezero, Sep 4, 2011
    Last edited: Sep 4, 2011
    I'm assuming you're taking algebra. Here's what they're asking:

    There are x runners in the race. A particular runner finished with 14 runners behind her and x/4 runners ahead of her. That means that

    x=15+x/4

    Multiply both sides by 4 and you get

    4x=60+x

    Subtract x from both side, and you get:

    3x=60

    Divide by 3 on both sides

    x=20

    She arrived in 6th place, BTW
     
  4. Madman100

    Madman100 Well-Known Member

    Jul 6, 2011
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    I'm purtty sure there is no proper answer to that particular problem. I could be wrong.
     
  5. Madman100

    Madman100 Well-Known Member

    Jul 6, 2011
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    If she finished in 6th, that would mean 5 people finished before her. Meaning 18 people finished AFTER her. 18 plus 6 does not equal 20 :(

    If she was in 8th, that would mean 7 people finished before her. Meaning 20 people finished AFTER her. 20 plus 8 DOES equal 28. :)

    Total participants is 28.
     
  6. mrchennyken

    mrchennyken Well-Known Member

    Mar 11, 2009
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    Yeah I got 28, thanks everyone!

    I did something like
    x = before
    y = after

    x - 13 = y
    x + y + 1 = 4y

    x = y + 13

    so

    y + 13 + y + 1 = 4y
    2y + 14 = 4y
    14 = 2y
    y = 7

    7 * 4 = 28
     
  7. squarezero

    squarezero Moderator
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    You are right -- I misread the problem.
     
  8. Random_Guy

    Random_Guy Well-Known Member

    Apr 6, 2009
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    Australia, mate!
    That was easy... I got it in like, 20 seconds.
     
  9. TiltMyTouch

    TiltMyTouch Well-Known Member

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    #9 TiltMyTouch, Sep 7, 2011
    Last edited: Sep 7, 2011
    Excellent work.
    .
     
  10. Eupatria

    Eupatria Well-Known Member

    May 18, 2011
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    That's the problem
    Big Apple
    You are killing me!!!
     

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