SOLUTION: Assuming there are 365 different birthdays, find the probability that of three people chosen at random:
a)no two will have the same birthday
b)at least two will have the sa
Algebra ->
Permutations
-> SOLUTION: Assuming there are 365 different birthdays, find the probability that of three people chosen at random:
a)no two will have the same birthday
b)at least two will have the sa
Log On
There are 365 ways out of 365 ways to choose the first person's birthday. Then, if you don't want the second person to have the same birthday, there are 364 ways out of 365 to choose the second person's birthday. And then 363 out of 365 for the 3rd person.
With 3 people there are only 3 possibilities, none have the same birthday, two have the same birthday, or all three have the same birthday. So .
I'll leave you alone to spend some quality time with your calculator.
By the way, the probability of no shared birthdays in a selection of people is
And .
The break even point is about and is near certainty when
John
My calculator said it, I believe it, that settles it
