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Question:


maganda123

There are 7 mysteries, 9 biographies, 2 reference books,and 10 picture books in the book bin at the library.

What are the odds of drawing a mystery book from the bin?

please help me answer this question.

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Posted by maganda123 on Sunday November 16, 2008 at 9:37 PM and tagged with math, odds.

Answers:

  1. plfoster
    plfoster Teacher
    High School - 11th Grade

    1 in 4....There are 28 books total...there are 7mysterys to the 28 total....so your chances of drawing a mystery would be 7 in 28 if it is reduced it would be 1 in 4.

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    Posted by plfoster on Monday November 17, 2008 at 8:45 AM

  2. cburr
    cburr Teacher
    Middle School

    eNotes Editor

    To figure out the probability (odds) of something happening, what you have to do is count up ALL the possibilities, and then count up how many of them involve the result you are looking for.

    In this case, there are 28 different books, so there is a total of 28 possibilities of what book will be drawn from the bin.   Since 7 of the books are mysteries, 7 out of the 28 possibilities will be mysteries.  From a math standpoint, this is 7:28 or 7 out of 28.  Since 7 goes evenly into 28 (4 x 7 = 28), you can reduce it to 1:4 or 1 out of 4.  

    It is important to remember that the probability is what would happen on average if you tried it many, many times.  You can't be sure that 1 of the first 4 books you actually pull on one try will be a mystery.  1 out of 4 is just the probable result.

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    Posted by cburr on Monday November 17, 2008 at 3:16 PM

  3. neon-ice-cream
    neon-ice-cream Student
    High School - 9th Grade

    7+9+2+10=28

    7/28

    1/4

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    Posted by neon-ice-cream on Sunday January 11, 2009 at 8:16 AM