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    Hi I've tried this question and I'm a bit stuck.

    Poppy rolls a dice. She keeps rolling until she rolls a 6. Work out the probability that Poppy rolls the dice:

    a)exactly three times
    b)fewer than three times
    c) more than three times
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    What is the probability that she doesnt roll a six in one throw?

    What is the probability that she rolls a six in one throw?
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    What is the probability of rolling a non-6? A 6?

    a. Three times requires non-6, non-6, 6
    b. Requires 6 OR non-6, 6
    c. Requires non-6, non-6, non-6
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    (Original post by Shaanv)
    What is the probability that she doesnt roll a six in one throw?

    What is the probability that she rolls a six in one throw?
    P(not6)=5/6
    P(6)=1/6
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    (Original post by isabel12144)
    P(not6)=5/6
    P(6)=1/6
    OK.

    a). So, to end up rolling the die exactly 3 times:

    What must she roll on the third throw?
    And what must she roll on each of the other two throws?

    Hence probability of exactly 3 rolls is...?
 
 
 
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