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Probability queston?

  1. Nov 4, 2007 #1
    1. The problem statement, all variables and given/known data
    You have 30 blue balls and 20 red balls in a box. You select one ball from the box. What is the probability of getting the red ball?, a blue ball?

    we can give the answer in percents or fraction(ratio)


    2. Relevant equations

    unknown. This is an extra credit thing and we were not given any help.. (ie.. equations, or other examples)

    3. The attempt at a solution
    Here is what I figure: 60percent of the balls are blue and 40are red.. so that was my answer .

    60% chance of a blue and 40%chance of a red.

    I am totally unsure on the specific formula to do this. Is my thinking correct?
     
  2. jcsd
  3. Nov 4, 2007 #2

    arildno

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    Well, you have been using the "formula" you were supposed to be using.

    What do you think a mathematical formula is?
    Nothing but the distilled logical relationship between precisely defined quantities.
     
  4. Nov 4, 2007 #3
    thanks for the help....
     
  5. Nov 4, 2007 #4

    malawi_glenn

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    What is the definition of % ?
     
  6. Nov 4, 2007 #5

    arildno

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    Conventionally, it means 1/100.
     
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