Table of Contents
- 1 What are the odds of 3 people being born on the same day?
- 2 How many people have a 50\% chance of sharing a birthday?
- 3 How many people need to be in a class before there is a greater than 50 chance that every day of the year someone has a birthday?
- 4 What is the probability of three people sharing a birthday?
- 5 What is the meaning of various probability?
- 6 How many people share a day of the week for birth?
What are the odds of 3 people being born on the same day?
The chances that a second baby is born on the same day as the first baby is 1 out of 365, said Rob Warren, director of the Minnesota Population Center and a sociology professor at the University of Minnesota. The chances that a third baby is also born on that same day is 1 in about 133,000, or about 8 in 1 million.
How many people have a 50\% chance of sharing a birthday?
two people
You can test it and see mathematical probability in action! 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.
How many people need to be in a class before there is a greater than 50 chance that every day of the year someone has a birthday?
For a greater than 50\% chance that one person in a roomful of n people has the same birthday as you, n would need to be at least 253.
What is the probability that two friends have same birthday in simple year?
What’s the chance that two people share the same birthday? The first person can be born on any day of the year, this means that the probability is 365/365 = 1. The second person has to be born on the same day as the first and there is a 1/365 chance of that happening.
How many people must be in a room for there to be 50\% probability that at least two of them share a birthday?
23 people
In a room of just 23 people there’s a 50-50 chance of at least two people having the same birthday. In a room of 75 there’s a 99.9\% chance of at least two people matching. Put down the calculator and pitchfork, I don’t speak heresy. The birthday paradox is strange, counter-intuitive, and completely true.
What is the probability of three people sharing a birthday?
$\\begingroup$ Empirically the answer seems to be $87$ or $88$. More precisely, the probability of at least three people sharing a birthday is very close to $0.50$ if there are $87$ people in total (making the standard assumption of an i.i.d. uniform distribution over $365$ days).
What is the meaning of various probability?
/ Various probability Calculates a table of the probability that one or more pairs in a group have the same birthday and draws the chart. n persons in a group (1) the probability that all birthdays of n persons are different.
This is easily seen when we consider the days of the week simplification. The chance that three people are born on the same day of the week is indeed 1 7 2, but the chance that three out of eight people share a day of week for birth cannot be ( 8 3) 7 2 because that exceeds 1. Thanks for contributing an answer to Mathematics Stack Exchange!
How much would it cost to get three people with the same birthday?
A computer calculation reveals that the only real root of this cubic polynomial is $N \\approx 83.13$. Hence we would expect to need $83$ or $84$ people in the room before having a 50-50 chance of getting three people with the same birthday. UPDATE:This is only an approximation, and it turns out it’s off by more than I expected.