What is the probability that three friends have same birthday?
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What is the probability that three friends have same birthday?
Since all probabilities are independent, we can calculate p = (1 – 1/365)*(1 – 2/365) = 132,132/133,225 ~ 0.99159. So, the probability of at least 2 of them having the same birthday (assuming independence) is 1 – p = 1,093/133,225 ~ 0.00820, close to 1 in 122.
What is the probability of 5 people having the same birthday?
2.7\%
Calculating the probability
| n | p(n) |
|---|---|
| 5 | 2.7\% |
| 10 | 11.7\% |
| 20 | 41.1\% |
| 23 | 50.7\% |
What is the probability of 2 friends having different birthdays?
Hence, the probability that two friends have different birthdays = 1 – 1365=364365.
How do I solve the birthday problem?
The first person covers one possible birthday, so the second person has a 364/365 chance of not sharing the same day. We need to multiply the probabilities of the first two people and subtract from one. For the third person, the previous two people cover two dates.
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.
When do you add a third term to a probability distribution?
First, it sounds as if it might include a case where $3$ people have the same birthday. Secondly, in 3., the third term is added when it should be subtracted (after changing it to be the probability of at least one pair, but no triples).$\\endgroup$
How many birthdays are there in the world?
There are 365 possible birthdays. (To keep the numbers simpler, we’ll ignore leap years.) The key to assigning the probability is to think in terms of complements: “Two (or more) people share a birthday” is the complement of “All people in the group have different birthdays.”