Dissecting the Birthday Paradox

Statistics isn’t always very intuitive

Photo by Adi Goldstein on Unsplash

Introduction

Try to answer this question without actually working it out.

How many people do you need in a room to ensure that there’s a 50% chance of any two people having the same birthday?

What would you answer purely based on intuition? What would a reasonable answer look like? 50 people? 100? 183? 365?

When I came across this problem, I guessed the answer to be about 70–80 …

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