Will rational tigers eat the lone sheep
Question
An island with plenty of grass holds tigers and sheep. Tigers can live on grass but prefer sheep. Only one tiger can eat a sheep at a time, and a tiger that eats a sheep turns into a sheep itself. Every tiger is perfectly rational and wants above all to survive. Does the sheep get eaten?
Short answer
No. Work up from small cases: with tiger the sheep is eaten; with , a tiger that eats becomes prey for the other, so none eats; with , eating leaves a safe 2-tiger situation, so one eats. By induction the sheep is eaten exactly when the number of tigers is odd, and is even.
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