Hi guys....

i dunt realli understand how to do this question:

what is the probability that a triple for a dice..will occur within the first 5 rolls?

also, im not sure if this is Binomal or geometric...

Thanks in advance.

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- May 5th 2010, 03:28 PMquestiongirlProbability Distrubution- Binomal or geometric?
Hi guys....

i dunt realli understand how to do this question:

what is the probability that a triple for a dice..will occur within the first 5 rolls?

also, im not sure if this is Binomal or geometric...

Thanks in advance. - May 5th 2010, 04:25 PMAnonymous1
- May 5th 2010, 05:13 PMquestiongirl
like getting triple 1s,2s,3s,4s..... for a dice. sorry i should have clarify the question.

- May 5th 2010, 05:23 PMAnonymous1
- May 5th 2010, 06:02 PMquestiongirl
- May 5th 2010, 07:08 PMAnonymous1
$\displaystyle Pr(\text{triple}) = \frac{6}{6^3} = \frac{1}{36}$ since there are $\displaystyle 6^3$ ways of rolling $\displaystyle 3$ die, and only $\displaystyle 6$ of the outcomes are triples.

The desired probability is:

$\displaystyle 1- [{5\choose 0}(\frac{1}{36})^0(1-\frac{1}{36})^{5-0}] = 1- (\frac{35}{36})^5 = \frac{71}{1296}$

Oh, and yeah, it's a binomial.