PBS Infinite Series

How Many Humans Have the Same Number of Body Hairs? (2016x3)

Air date: Dec 01, 2016

Do two people on the planet have the exact same number of body hairs? How about more than two? There’s a simple yet powerful mathematical principle that can help you find out the answer. Kelsey Houston-Edwards breaks down the Pigeonhole Principle and explains how it can be used to answer some pretty perplexing questions.