Same Birthday Math Problem

Some people may think.

Same birthday math problem. Other birthday problems first match. In the standard case. Very strange even the chinese and foreign masters can not explain. Multiply those two and you have about 0 9973 as the probability that any two people have different birthdays or 1 0 9973 0 0027 as the probability that they have the same birthday.

The birthday problem asks how many people you need to have at a party so that there is a better than even chance that two of them will share the same birthday. Assume 365 days in a year. The birthday paradox is strange counter intuitive and completely true. 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.

Please calculate and see if the answer is 2019. In a room of 75 there s a 99 9 chance of at least two people matching. The birthday problem also called the birthday paradox deals with the probability that in a set of n n randomly selected people at least two people share the same birthday. It s only a paradox because our brains can t handle the compounding power of exponents.

This year your age your year of birth each individual is 2019. 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. Same birthday as you. For k 12 kids teachers and parents.

The first person could have any birthday p 365 365 1 and the second person could then have any of the other 364 birthdays p 364 365. In the birthday problem neither of the two people is chosen in advance. Math explained in easy language plus puzzles games quizzes worksheets and a forum. 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.

There are 30 people and 365 days so 30 365 sounds about right. What is the chance that any two of them celebrate their birthday on the same day. Though it is not technically a paradox it is often referred to as such because the probability is counter intuitively high. Is this really true.

A related question is as people enter a room one at a time which one is most likely to be the first to. It s a thousand year wait. Put down the calculator and pitchfork i don t speak heresy.