26 students, all either always tell the truth either always tells lies
Source: Caucasus 2015 7.4
April 26, 2019
combinatoricsTrue or False
Problem Statement
There are students in the class.
They agreed that each of them would either be a liar (liars always lie) or a knight (knights always tell the truth).
When they came to the class and sat down for desks, each of them said: “I am sitting next to a liar.”
Then some students moved for other desks. After that, everyone says: “ I am sitting next to a knight .”
Is this possible?
Every time exactly two students sat at any desk.