TED-Ed: Check your intuition: The birthday problem - David Knuffke

The video explores the birthday problem, which shows that in a group of 23 people, there's a 50.73% chance that two people share the same birthday. This counterintuitive result is explained using combinatorics, focusing on calculating the probability of no shared birthdays and then subtracting from 100%. The video highlights the rapid growth of possible pairs as group size increases, making shared birthdays more likely. It concludes with real-world examples, illustrating how math can reveal unexpected probabilities.

What is the minimum group size needed to have a greater than 50% chance of two people sharing a birthday?

Explain why our intuition about the birthday problem is often incorrect.

Describe the method used to calculate the probability of no birthday matches in a group.

What is the probability that at least one birthday match occurs in a group of 23 people?

How does the number of possible pairs in a group relate to the probability of a birthday match?

How many possible pairs are there in a group of 10 people?

What does the birthday problem illustrate about coincidences in probability?