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December 26th, 2006, 11:51 AM   #1
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Cards

If a card has drawn from a regular 52 card deck, what is the chance that the card will be either a 2 or a heart , or the 2 of hearts.
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December 26th, 2006, 01:53 PM   #2
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I'd say that it's
1/13 + 1/4 - 1/52= 16/52

because the probability of choose a two is 1/13, and the probability of choosing a heart is 1/4, and the probability of finding the two of hearts must be subtracted, since it's included in both probabilities at once, but should only be included in one. In other words, find all the hearts and then all the twos that aren't also hearts, add them up and divide by 52.
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December 26th, 2006, 03:15 PM   #3
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What, infinity, don't you know how to reduce fractions? :P
Anyway, the reduced answer is 4/13.
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December 26th, 2006, 04:33 PM   #4
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What, infinity, don't you know how to reduce fractions? :P
Yeah, but I've been oxidized so much lately that I forgot how to reduce.
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December 26th, 2006, 06:08 PM   #5
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Counting: A♥, 2♥, 3♥, 4♥, 5♥, 6♥, 7♥, 8♥, 9♥, 10♥, J♥, Q♥, K♥, 2♠, 2♣, 2♦ = 16
16/52 = 8/26 = 4/13.

Figuring: 13 hearts + 4 2s - 2♥ (otherwise counted twice) = 13+4-1 = 16
16/52 = 8/26 = 4/13.

Fractions: 1/4 + 1/13 - 1/4 * 1/13 = 4/13
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December 27th, 2006, 08:14 AM   #6
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Quote:
Originally Posted by CRGreathouse
Counting: A♥, 2♥, 3♥, 4♥, 5♥, 6♥, 7♥, 8♥, 9♥, 10♥, J♥, Q♥, K♥, 2♠, 2♣, 2♦ = 16
16/52 = 8/26 = 4/13.
How did you do the card suits?
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December 27th, 2006, 10:21 AM   #7
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Quote:
Originally Posted by roadnottaken
How did you do the card suits?
I knew they were standard characters, so I googled for them and pasted them in.
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December 30th, 2006, 01:10 PM   #8
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I just split off the last post and made it a new topic.
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