A brain teaser where n number of people stand in a circle; the first person has a sword and kills the next alive person beside him and passes the sword on. We have to find the last person alive among the n people in the circle.
If the total number of people are 5, 1 kills 2, passes the sword to 3. 3 kills 4, passes the sword to 5. 5 kills 1, passes the sword to 3. 3 kills 5 and is the last man to hold the sword as the rest are dead. Hence, answer is person 3 if there are a total of 5 people.
Similarly, if the total number of people are 100, the answer (i.e. the last man) turns out to be person 73.