Table of Contents
- 1 What is the probability that in a group of 40 people 2 or more people have the same birth month and day?
- 2 What is the probability that in a room of 30 people there is a pair of people who have the same birthday?
- 3 How many people in a group of N have the same birthday?
- 4 What is the general birthday problem in statistics?
What is the probability that in a group of 40 people 2 or more people have the same birth month and day?
Probability of Shared Birthdays or, How to Win Money in Bar Bets
| Probability in a group of n people that 2 or more have the same birthday | |
|---|---|
| 23 | 0.507 |
| 30 | 0.706 |
| 40 | 0.891 |
| 50 | 0.970 |
What is the probability that in a room of 30 people there is a pair of people who have the same birthday?
The probability of sharing a birthday = 1 − 0.294… = 0.706… Or a 70.6\% chance, which is likely! So the probability for 30 people is about 70\%.
What is Birthday paradox in DAA?
Persons from first to last can get birthdays in following order for all birthdays to be distinct: The first person can have any birthday among 365. The second person should have a birthday which is not same as first person. The third person should have a birthday which is not same as first two persons.
What is the probability that two people have the same birthday?
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). 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.
How many people in a group of N have the same birthday?
The problem is to compute an approximate probability that in a group of n people at least two have the same birthday. For simplicity, variations in the distribution, such as leap years, twins, seasonal, or weekday variations are disregarded, and it is assumed that all 365 possible birthdays are equally likely.
What is the general birthday problem in statistics?
The generalized birthday problem. Given a year with d days, the generalized birthday problem asks for the minimal number n(d) such that, in a set of n randomly chosen people, the probability of a birthday coincidence is at least 50\%.
What is the probability of 30 birthdays?
Therefore, the total combination of all the possible probabilities of birthdays for all of the 30 people is 365 * 365 * 365 * … 30 times or, better expressed, 365^30.