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Englisch A risky wager.

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alt A risky wager.

Lee
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You are at a party with a friend. There are 20 people present including you and the friend. your friend makes you a wager that there are no two people at this party with the same birthday. Would you make the wager?

Note: Birthdays are identical if their month and date matches up. Year, hour, minute, seconds, are not part of the requirement.
1× editiert, zuletzt 14.04.10 07:02:51

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Lee
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If there are 20 people, would you bet that there are at least 2 people who share the same birthday?

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ohaz
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I would do this:
Spoiler >
1× editiert, zuletzt 14.04.10 07:20:49

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bezmolvie
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Well, depends, as at 23 people it just nears 50%, so I want to know how much I'm betting.

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Lee
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That's essentially correct, although @TKD: 356 instead of 256 xD.

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sonnenschein
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if the party is clearly for a single man, why anyone would even come if they have birthday. they would probably make their own.
also, 20 people are mostly friends and family so you should know when is their bday

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DC
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nobody said that it is a BIRTHDAYparty
Spoiler >

alt Re: A risky wager.

ohaz
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oh, well, I calculated with the right numbers, just wrote it down the wrong way...
In fact, it's even an unfair game. I calculated the chance, that no two people have the same birthday. So the chance, that two people have the same birthday is 100%- my calculated chance. Depends on which side you have to chose when your friend makes the wager!

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sonnenschein
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DC hat geschrieben
nobody said that it is a BIRTHDAYparty
Spoiler >

ah crap, you are right
I guess that changes alot of things

alt Re: A risky wager.

Relapse
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Bloodshot hat geschrieben
Well, depends, as at 23 people it just nears 50%, so I want to know how much I'm betting.

did you look that up on wikipedia?

alt Re: A risky wager.

YellowBanana
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Depends on the odds I'm getting.

The chances 2 people don't share the same birthday in a party of 20 people is:

(365!/(365^n (365-n)!)) for n = 20,

so that's about 58.8%. If my odds are better than 10:7, i'm taking it

If the odds are 1:1,

I'm winning 0.588 * (2 * amount) - amount in a long term

alt Re: A risky wager.

Banaan
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I'd certainly take the bet
(knew this one, but then with a football team)
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