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# Birthday paradox - Try this out Watch

1. October 20th anyone?

Seen 19th and 21st but not 20th.
2. (Original post by SophieGloria)
29th March.
I found my twin !

Posted from TSR Mobile
3. (Original post by Krish4791)
1st September.
My sister birthday.
4. 4th April?
5. 18th October
6. 5th May

(Original post by ramkanwar55)
may 5th guise

7. (Original post by NiceToMeetYou)
Hey there =]

Don't know if you've heard of the birthday paradox, but it basically states that once you reach 57 people in a room there is a 99% chance that they share the same birthday.

So to try this out, just post your birthday and we'll see how many people it takes before a birthday is shared

To start off - June 18th
I've done a quick example of how the chance of two people having the same birthday increases faster than the number of people in the group. Each line represents the chance of the two people having the same birthday (1/365). So totalling the number of lines gives you the chance two people will have the same birthday out of the whole group. It soon gets too difficult to do by hand though. I'd have to dig out my old statistics book to find a formula.

I hope the image and my handwriting are ok!
8. March 25th
9. This applies if every DOB is same likelihood of happening. Go through when most people from school/who you know have their birthdays, take off 9 months or so, you'll see when a lot of people were conceived. It isn't random.
10. (Original post by jqian)
Nice, my dad's birthday is on the 24th June. My proper exams start on my birthday and finish on my dad's birthday.
My final exams on my birthday :P Yours seem later than most?
11. (Original post by speedyqueen)
30th November
(Original post by pjm600)
30th november
Birthday buddies
12. (Original post by magicmuggle)
Me too! 3rd March ftw
Ooooh yea high five!
13. 8th November
14. june 10th
15. 28th April
16. (Original post by TLK)
August 24th!
BINGO!
17. (Original post by IcEmAn911)
28th April
You share a birthday with my grandmother; does that count...?
18. 29 oct
19. (Original post by SwitchingOne)
8th december
8th December

Spoiler:
Show
Hi twin!!11!211!!
20. 223 posts. No one shares my birthday. Let's see how long this goes.

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Updated: June 9, 2017
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