The Pixie and the Sprite
by Jason Ross
You are lost in the woods. You come to a T-junction and are wondering which way to go. You have a funny feeling that one way will get you out, the other will mean certain death. Weird, eh?
A pixie approaches you.
“A left turn will get you out of the woods,” it advises.
A nearby sprite hears this and calls out, “Beware of him. He lies!”
“Exactly 4 times out of 10, I do!” the pixie retorts, and disappears.
You know from folklore that all sprites always tell the truth. You also know that throughout their life, an individual pixie tells the truth a certain number of sentences out of ten, determined by chance at birth. You also know this number is an integer.
Which way should you turn to maximise your chance of escape?
