What are some examples of challenging logical puzzles and questions?

[Evo]

No more conflicts with the answer will be entertained by physixguru.I have had a talk with the moderators and anybody looking to argue on the answer,after i have mentioned,they are not mine, will be barred from answering the questions in the thread.

This is my forum and you did not get that approval from me.

Since this isn't a thread that all can sincerely play in, locked.