Introduction
This lesson involves Maths
The Birthday Paradox says that if there are 23 people in a room, the chances are better than 50% that two or more of them share a birthday.
That means the probability is greater than 0.50 that two people were born on the same day of the year.
That doesn't seem possible, but it works.
Note: it won't work all the time, but it should work about 50% of the time.
We can test this with a Python program. This makes repeating the test pretty simple.
Assumption: I'm ignoring leap year birthdays for now. It does work even with leap years, but is harder to write the program.