SOLUTION: What is the probability that it will take at most 3 throws until a six occurs on a dice

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Question 1152095: What is the probability that it will take at most 3 throws until a six occurs on a dice
Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
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I edited your post in THIS WAY : 

    When rolling a dice, what is the probability that it will take at most 3 throws until a six occurs on a dice ?


Solution 

    P =   P(getting 6 at the first rolling) + 

        + P(getting 6 at the second rolling and not getting it at the first rolling) + 

        + P(getting 6 at the third rolling and not getting it NEITHER at the 1-st NOR at the 2-nd rolling) = 


        = 1%2F6 + %285%2F6%29%2A%281%2F6%29 + %285%2F6%29%2A%285%2F6%29%2A%281%2F6%29 = 

        = 1%2F6 + 5%2F%286%2A6%29 + 25%2F6%5E3 = 6%5E2%2F6%5E3 + %286%2A5%29%2F6%5E3 + 25%2F6%5E3 = %2836+%2B+30+%2B+25%29%2F6%5E3 = 91%2F216 = 0.421296 = 42.1296%.    ANSWER

Solved.