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Homework Help: Mental Lapse

  1. Jan 7, 2005 #1
    Hello all

    I am having a little mental lapse.

    If the average score of p students is 70 and the average score of n students is 92, and the average of the scores of p and n is 86, what is p/n?

    (70p + 92n)/ ( p + n ) = 86

    70p + 92n = 86(p+n)

    70p + 92n = 86p +86n
    92n = 16p + 86n
    6n = 16p
    p = 3/8n
    n= 8/3p

    Where do I go from here (sorry was awake for whole night)

  2. jcsd
  3. Jan 7, 2005 #2


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    Unless you're given either n or p, you're done. You have the ratio between n and p.

    If n is 24 students, then p is 9 students; if n is 48 students, then p is 18 students, etc.
  4. Jan 7, 2005 #3


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    You're 'home'. :smile:If
    [tex] p=\frac{3}{8}n [/tex]
    [tex]\frac{p}{n}=\frac{3}{8} [/tex]


  5. Jan 7, 2005 #4

    thanks dextercioby

    guess it was because i stayed up
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