Birthday Problem Explained Math

The birthday paradox also known as the birthday problem states that in a random group of 23 people there is about a 50 percent chance that two people have the same birthday.

Birthday problem explained math. It all started when kenneth kong a television show host in singapore posted the following. We ve taught ourselves mathematics and statistics but let s not kid ourselves. Ok fine humans are. Numerical evaluation shows rather surprisingly that for n 23 the probability that at least two people have the same birthday is about 0 5 half the time.

Same birthday as you. Recently a thought provoking problem was popularized. 11 12 10 12 9 12 8 12 7 12 0 22. Humans are a tad bit selfish.

Take a look at the news. This is the numerator of. So the chance of not matching is. 365 times 364 times cdots times 366 n.

The number of ways that all n people can have different birthdays is then 365 364 365 n 1 so that the probability that at least two have the same birthday is. Notice how much of the negative news is the result of. Flip that around and we get the chance of matching. 365 365 days when the order in which you pick the birthdays matters is.

If you just want the answer and you don t want to read the explanation below then click here. In the standard case. The cheryl s birthday problem. So there is a 78 chance of any of them celebrating their birthday in the same month.

The birthday problem for such non constant birthday probabilities was tackled by murray klamkin in 1967. This is because each successive birthday has one fewer choice of days left. A related question is as people enter a room one at a time which one is most likely to be the first to. N n distinct birthdays from a set of.

In the birthday problem neither of the two people is chosen in advance. Cheryl math problem explained. When was cheryl s birthday. Understanding the birthday paradox problem 1.

Is this really true.