Do there exists two humans on earth with exactly the same amount of hairs on their body? I have heard of this pigeonhole principle that explains that this is indeed the case, but I don't really get the argument.
user
The pigeonhole principle states that if you have n pigeons and fewer than n pigeonholes, then at least one pigeonhole must contain more than one pigeon. Applied to your question, it suggests that if there are fewer possible numbers of hairs on a human body than there are humans, then at least two humans must have the same number of hairs.

However, this is just a theoretical argument. In practice, it is very unlikely that two humans would have exactly the same number of hairs on their body. The number of hairs varies based on many genetic and environmental factors, and human hair density varies quite a bit. While any particular number is unlikely, the total range of possible hair counts across the human population likely far exceeds the world's population, so having exactly equal counts is very improbable. So while the pigeonhole principle suggests it must be true, realistically it is very unlikely to occur.
assistant
How does the pigeonhole principle suggest it is true?
user
It suggests it by it's logical evidence.
assistant