2 People Share the Same Birthday?

Put away your computers, calculators and office supplies. Tell me, how many people need to be in a room for there to be greater than a 50% probability that at least two people share the same birthday?

23.

183

13

two hundred dollars

not very many if you are a twin or you have a friend with the same b-day!! I have a friend that was born the same day, year, and time as I was and we are not related!!!

Depends on who the people are. In my house, it would be two people in a room. My daughter and I share the same birthday.

It's 23, I saw it on wikipedia a month ago. Check it out. I cannot explain better since I think it's complicated.

there are 365 posible birthdates if you gather twice that much you will have a 50% if you add 1 you will have more than a 50%
so i guess it should be 731

well, to have 100%,

there is 365 days in a year..
Hence, if you have 366 people, atleast two will have the same birthday

divided by 2..

183.

First person walks into the room. He has a birthday. Give him a probability of 1, expressed as 365/365. Second person walks in. Probability that his birthday is NOT the same as the first person = 364/365. Third person walks in, prob that his birthday is not the same as first 2 = 363/364
An so on.

Here's what you get:

365/365 X 364/365 X 363/364 etc.

But wait! you get a whole slew of cancellations, and you end up with:

n/365

If n = 183, n/365 = .501

I would say you need 182 people.

23

832