# Probability - rolling 2 dice

1. Feb 22, 2012

### XodoX

1. The problem statement, all variables and given/known data
Two dice are rolled. What is the probability that at least one is six? If two faces are different, what is the probability that at least one is six?

2. Relevant equations

3. The attempt at a solution

I have no clue. Although the first one shouldn't be that hard, but it's "at least", so I don't really know. 1-P(0), I guess, but I'm not sure how to get P(0).

2. Feb 22, 2012

### jbunniii

What is the complement of the event "at least one is six"?

3. Feb 22, 2012

### XodoX

0 six

4. Feb 22, 2012

### jbunniii

OK, so what's the probability of rolling two dice and getting no sixes?

If you're not sure about this, how about first answering the simpler question: what is the probability of rolling one die and getting no six?

5. Feb 22, 2012

### DaveC426913

Not that I recommend this but this problem is simple enough that you could solve it using brute force by writing all combos out. i.e. There are exactly 36 possible combinations of 2 dice. How many of those combinations contain at least one six?

Then, you can go back and generalize the principle that lead you to that answer.

6. Feb 22, 2012

### XodoX

Alright. Thank you. I got it now.

7. Feb 22, 2012

### DaveC426913

So, now that you know the principle, can you apply it? If you had 3 six sided dice, could you say the odds that at least one six turns up?

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