Friday, April 30, 2010

Truth tellers and Liars

Here is famous puzzle pattern, I wish to put in the following way.

Assume three friends A, B and C are sitting on a concrete wall. The friends always tell either truth or always lie, and they knew each other who tell truth. One person, asked A, “are you a truth teller”? A said something but the person could not able to listen.

The person asked B, what did A said? He replied “A says he is always truth teller”.

Again, the person asked C, what did A said? He replied, “B is lying”.

Question is, C – truth teller or liar?

Hint: The answer is obvious. We need to transform these statements into mathematics. There is a branch of mathematics called connectives. We can make use of them to arrive at solution.

The connectives are AND (conjunction), OR (disjunction), Conditional (if then) and Bi-conditional (if and only if). Make truth tables for each and relate them with statements.

We can make many of such puzzles based on the connectives properties.

No comments: