Probability
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Dr.Peterson
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What have you tried, and where do you need help? (You did read the posting guidelines, right?)
I would probably do this by combinations.
I would probably do this by combinations.
I need a formula
That's cool. Now read the posting guidelines.
Dr.Peterson
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We need to know what you have learned. Anything you can tell us may help us see the best hint we can give.
But here is the formula: [MATH]\text{probability} = \frac{\text{number of ways to choose } m \text{ tickets, } l \text{ of which are winners}}{\text{number of ways to choose } m \text{ tickets}}[/MATH]
I presume you have learned at least that much (the definition of probability); and since you didn't ask anything about combinations, I am guessing that you know how to do them.
You also need to determine for sure whether you need exactly l winners, or at least l winners.
But here is the formula: [MATH]\text{probability} = \frac{\text{number of ways to choose } m \text{ tickets, } l \text{ of which are winners}}{\text{number of ways to choose } m \text{ tickets}}[/MATH]
I presume you have learned at least that much (the definition of probability); and since you didn't ask anything about combinations, I am guessing that you know how to do them.
You also need to determine for sure whether you need exactly l winners, or at least l winners.
Steven G
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Before you can 'need a formula' you need to think about the problem so that hopefully you would know what formula to use.
Can you tell us what is preventing you from just doing the problem? If we know what you are think then possibly we can guide you in the right direction.
Please post back.