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Thread: please help probability question

  1. #1
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    please help probability question

    Three fair 6 sided dice are rolled. Find the probability that the total on all three dice is 5 or less.?
    ans10/216 pleease explain your method :-)
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  2. #2
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    Re: please help probability question

    Hello, aimsywamesy!

    Three fair 6-sided dice are rolled.
    Find the probability that the total on all three dice is 5 or less.
    Ans: 10/216

    There are: 6^3 = 216 possible outcomes.


    Outcomes with sums \le 5

    . . \begin{array}{c} (1,1,1) \\ (1,1,2)\;(1,2,1)\;(2,1,1) \\  (1,1,3)\;(1,3,1)\;(3,1,1) \\ (1,2,2)\;(2,1,2)\;(2,2,1) \end{array} . . 10 outcomes


    Therefore: . P(\text{sum}\le 5) \;=\;\frac{10}{216} \;=\;\frac{5}{108}
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  3. #3
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    Re: please help probability question

    Quote Originally Posted by aimsywamesy View Post
    Three fair 6 sided dice are rolled. Find the probability that the total on all three dice is 5 or less.?
    ans10/216 pleease explain your method :-)

    There are 216 possible triples.

    Make a list of favorable outcomes.
    We can get 1,1,1 in one way.
    We can get 1,1,2 in three ways: 112, 121, 211.
    Same for 113. So far that is seven favorable outcomes.

    According to the give answer you should find ten in all.

    Or go to this webpage add up the coefficients of x^3,~x^4,~\&~x^5.
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  4. #4
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    Re: please help probability question

    "Two great minds with a single thought!"
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