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Math Help - Last question for the day...

  1. #1
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    Question Last question for the day...

    You have a chance to win a prize by picking 5 numbers from 42, (no repeat) what is your chance to win if:

    a. order is important
    b. order is not important
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  2. #2
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    Quote Originally Posted by SMS386904 View Post
    You have a chance to win a prize by picking 5 numbers from 42, (no repeat) what is your chance to win if:

    a. order is important
    b. order is not important
    Assuming the numbers are not replaced after each draw:

    a. (\frac{5}{42}) (\frac{4}{41}) (\frac{3}{40}) (\frac{2}{39}) (\frac{1}{38}) = \frac{5!}{(42)(41)(40)(39)(38)}

    b. ^nC_r = \frac{n!}{(n-r)!r!} where n = 42 and r = 5

    = \frac{42!}{(42-5)!5!}
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