Board Thread:Fun and Games/@comment-48285-20141111171111/@comment-17259909-20150802011930

Imagine a bathroom with 100 urinals all lined up in a row. There's enough room in the bathroom to serve 100 people, but unfortunately, everyone's too nervous to go the bathroom next to each other!

What is the minimum number of people such that an arrangement of these people in the bathroom forces the next person who enters the bathroom to use one next to someone else?

Source: brilliant.org