Super-Paradox

I’d heard somewhere that in a group of about 30 people, the chances that two share a birthday is pretty good.  Well, it turns out, that’s actually the case.  It’s called “the Birthday Paradox,” and it’s even more interesting than that — in a group of only 23 people, there is about a 50% chance that two will share a birthday (you can watch the attached video for the math on that).

But I’m here for something else – something a bit related. Because long ago, when I was coming back from Korea for the first time with a wife and child, we gathered around the family table and realized we had quite the birthday paradox going. A super-paradox.

I can’t remember the exact numbers we had there – I’d estimate nine people total.  I think at that time (early 1988), all of my brothers and sisters lived out-of-state save one.  My family totaled three, my oldest sister’s family was four, and then my mother and father.  I could be wrong, and maybe someone can correct me but nine is an entirely probable number.

So of the nine:  my son and my sister’s husband shared a birthday.  My mother and her first grandchild (my sister’s first daughter) shared a birthday. And – I’m bringing this up now, because today is the day – my father and my wife shared a birthday.

Happy birthday, Micha.  And if you’re keeping track, the lottery numbers should be: 3 10 11 13 14 29.