IEEE Weekly Puzzle #30 – Truthful/Liar/Uncertain

15 December 2014 Comments Off on IEEE Weekly Puzzle #30 – Truthful/Liar/Uncertain

In a room we have 20 people who either lie, tell the truth or are uncertain. Those who tell the truth always tell the truth; those who lie always lie; and those who are uncertain randomly tell the truth at times and lie at other times.

Everyone in this group of 20 people says that there is at least 1 liar among them. Find the number of liars, the number of individuals who tell the truth, and the number of those who are uncertain.

Prize: Toshiba 8GB USB Flash Drive

Send your answer to by 5:30 p.m. on December 23, or visit to submit your answer online, and get a chance to win the prize!

This question was prepared by Emrehan Halıcı, president of the Turkey Intelligence Foundation