Happy Birthday! (2 Viewers)

Stephan

Senior Member
Nov 9, 2005
16,403
If no two share a birthday then the first person can choose a birthday
in 365 ways, the second person in 364 ways, the third in 363 ways, and
so on. If there are n people in the room, the probability that no two
share a birthday is

365 x 364 x 363 x ... x (365-n +1) P(365,n)
---------------------------------- = --------
365^n 365^n

So the probability that two at least share a birthday is:

P(365,n)
1 - --------
365^n​
.........................................................P(365,n)
If this must be >= 0.5 then we require -------- <= 0.5
..........................................................365^n

(Here, P(365,n) is the number of permutations of n things that can be
made from 365 different things)

There is no easy way to solve the equation for n, but with a
calculator which gives permutations and combinations, trial and error
will quickly establish that n must be around 23.

P(365,23)
--------- = 0.4927
365^23

and 1 - 0.4927 = 0.5073

and so 23 people are sufficient to make the probability of a shared
birthday greater than 50%. this means that 33 people are more than enough.


Give me my money :D
:lol: Get out of here.
 

Dostoevsky

Tzu
Administrator
May 27, 2007
88,458
Of course you aren't gay. We don't have gays in the Balkans. They all live in USA, Western Europe and the Arab world.

What happened with that girl, btw?
Indeed.

I don't know...I guess she finds it hard to give you that money. :p Or she had to run to school to tell the answer because she couldn't answer it herself.
 

Alen

Ѕenior Аdmin
Apr 2, 2007
52,582
Indeed.

I don't know...I guess she finds it hard to give you that money. :p Or she had to run to school to tell the answer because she couldn't answer it herself.
I'm not asking you about Hoori, you fool. I'm asking about "Toma Zdravkovic" :p

P.s: And Hoori paid me the money right away. I had 30k now i have 130k.
 

Dostoevsky

Tzu
Administrator
May 27, 2007
88,458
Oh, you're shooting high i see.
Expect a disappointment :D
sorry for this...last time.

nije bas i bilo kao sto izgleda, ja nju znam od skoro i znam da je drugarice iz mog odeljenja mrze (a mene one nerviraju :D)pa sam hteo da ih zajebavam malo i uspelo je :lol:.Odma ko da ih je pukla ljubomora i krenula da kreste...guske glupe. :D Ali Boze moj, dobra je skorz.
 

Alen

Ѕenior Аdmin
Apr 2, 2007
52,582
sorry for this...last time.

nije bas i bilo kao sto izgleda, ja nju znam od skoro i znam da je drugarice iz mog odeljenja mrze (a mene one nerviraju :D)pa sam hteo da ih zajebavam malo i uspelo je :lol:.Odma ko da ih je pukla ljubomora i krenula da kreste...guske glupe. :D Ali Boze moj, dobra je skorz.
Hmmm, why did you say then, here on the forum, that you're in love?
Don't lie Dusan, you're in deep shit, you're in love. :D
 

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