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Anyone up for a funny math problem?
- Thread starter Jade Cambell
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Thanks guys. So I guess the chances are about 1 in 177979. If anyone else has any insight or input, i'd love to hear it.
And no, this isn't for school. This is a real life situation which seemed very unlikely, so I wanted to figure out what the chances were.
And no, this isn't for school. This is a real life situation which seemed very unlikely, so I wanted to figure out what the chances were.
This reminds me a bit of the problem with the 2 football teams.
If there are 22 players on the pitch, the chances of 2 of them sharing the same birthday is actually >0.5.
Although I think that's a much better maths problem.
Actually, it's slightly less than 0.5. 23 people is about the 0.5 mark
This reminds me a bit of the problem with the 2 football teams.
If there are 22 players on the pitch, the chances of 2 of them sharing the same birthday is actually >0.5.
Although I think that's a much better maths problem.
You've lost me. How does that compute?
Just curious to see the math behind it.
You've lost me. How does that compute?
Just curious to see the math behind it.
Total number of ways that 22 people can have birthdays: 365^22
Ways that sees everyone have a unique birthday: 365*364*363*362*...*345*344
Thus, probability all 22 players have different birthdays = 365*364*363*362*...*345*344 / 365^22 = 0.524
Thus, probability that all 22 birthdays are not unique = 1 - 0.524 = 0.476
-----------------------------
For 23 people it is 0.507
That was the first thought that came to my head when I opened the thread.
C'mon Q, we need you!
tricky title!
no help here. i read the title and was expecting something else.
these two integers walk into a bar...
no help here. i read the title and was expecting something else.
these two integers walk into a bar...
Wonderful!
Surprised he hasn't already provided input!That was the first thought that came to my head when I opened the thread.
C'mon Q, we need you!
Good point!
LOL.
Unfortunately, probabilistically, you can't do that. It's much harder to incorporate leap years
Isn't it still fairly straightforward? Take the odds of the two days being the same as you have done but not Feb 29 and add in the probability of one date actually being Feb 29?
The chance of two someone's birthday being Feb. 29 are ~ (1/(365+365+365+366))^2 and then you still have 364/(365*365). i.e. the total chance is only one in a U.S. billion i.e. ~1E-9.
B
No more probability! I just got done (almost certainly) failing a Probability/Stats final this morning... Also, I'm pretty sure Dr. Q's input is not needed, as swiftaw's answer is correct (although you probably don't believe me, seeing as I just failed my exam ).
Also, I'm pretty sure Dr. Q's input is not needed, as swiftaw's answer is correct (although you probably don't believe me, seeing as I just failed my exam ).
It is right, but this answers the likelihood of these 2 people's paths crossing how?
I had a friend in grade school where he had the same birthday as my dad, and I had the same birthday as his dad.... and my home town only has 1600 people or so...
It is right, but this answers the likelihood of these 2 people's paths crossing how?
That wasn't the same problem. The one you quoted was a new problem posed by someone else.
Well you guys probably have similar taste.
1600 people means that there should be five birthdays/day on average. Considering that, I'd say the odds are fair for that to be the case.
Well you guys probably have similar taste.
Both holidays were tours, never staying in one place for more than 2 nights...
I guess we're surrounded by amazing co-incidences all the time, and when we actually notice some of them (the birthdays, for example) we're amazed.
It's one thing for random people to have the same birthday, but to keep it in families? His dad and I shared a birthday and he and my dad shared one as well. Given the low number of people in the town lessens likelihood of the reciprocal relationship.
Well that's true, but it's nowhere near as amazing as the fact that my cousins share the same birthday, and they're sisters!
Well that's true, but it's nowhere near as amazing as the fact that my cousins share the same birthday, and they're sisters!
Was either born by cesarian section? Does the birthday happen to fall around 9 months after your uncle's birthday?
Was either born by cesarian section? Does the birthday happen to fall around 9 months after your uncle's birthday?
Just goes to show you, we might think these coincidences are "amazing" but they're really not when you step back and think about it.