Probabilities

Today is my wife’s birthday. It is also her great aunt’s birthday. It is also our daughter’s birthday.

So the natural question arises. What is the chance of that? And should we then play the lottery and hope to win $200M?

Let’s focus on the first. Even though these are family members, statistics do not care. As such each ‘event’ is considered independent of one another. Logically, each probability is then 1/365 (ignoring leap years for practical reasons).

Thus the total probability of any three people have the same birthday is a 7.5 in 1 million chance, or 1 in ~133,500.

Not near as remote as you would initially think. Not near the remote odds of winning the lottery.

So as for the second question above: Oh well, guess that $200M will go to someone, eventually……