A distant planet is inhabited by creatures having more than two arms. The ones with an even number of arms are the knights who always tell the truth; the ones with an odd number of arms are the liars who always speak falsely.

Four inhabitants are conversing amongst themselves:

• The green one says, "I have ten arms. The blue one has only eight arms."
• The blue one says, "I have ten arms. The green one has nine arms."
• The red one says, "The blue one has ten arms. I have eleven arms."
• The striped one says, "None of the four of us except myself have ten arms."

Which of the four inhabitants has exactly ten arms?

(In reply to Correct solution by Math Man)

Excellent.

I've modigied my post to direct readers here.

Posted by Charlie on 2012-12-22 09:58:13