What is the probability that on campus of 730 students there exists at least one triplet of students celebrating their birthday on the same date?
Rem: Assume a year of 365 days
It's about 99.999999999999999999999999999999999999999%. (I haven't really done the math, so I don't know how many more 9's there are, but there are a lot). This is a near-certainty. The only way to not have a triplet is if there were two people born on each of the 365 days in the year.