I just came across this tweet and thought it would be fun to share here:
Josh Wolfe@wolfejosh
PUZZLE:
100 people line up to take their seats in a 100πΊtheater
The 1st in line lost her π
sits in aπΊat random
Each remaining theatergoer sits in their assignedπΊunless it's occupied & then sits in a randomπΊ
What's the probability the last person in takes their assignedπΊ?02:48 AM - 20 Jul 2018
It looks like some people in the Twitter replies have already come up with a solution, but I thought it would be a fun puzzle nonetheless!
Top comments (2)
Here's my simulation in Ruby. I know that one million is overkill, Lol
Spoilers below β
It's 50%, apparently!
When the 100th person enters, the occupied seats are 99, so the seat is either his or it isn't. Hence 50%, matches with the twitter feed. Not sure if this approach is right though.