Three explorers are getting kidnapped by an evil tribe deep in the jungle, and their life now depends on their ability to correctly answer the following challenge the evil tribe's chief has for them. The explorers are tied to three trees facing each other and are presented with the chief's 5 wives: 3 brunettes, and 2 blondes. The three explorers are now blindfolded, and the chief picks three of his five wives to stand behind the trees the explorers are tied to, one behind each tree. The remaining two wives disappear from view. Then the blindfolds come off, and each explorer is able to see the two wives that are standing behind his two colleagues, but not the one behind himself. Each explorer now has up to 10 minutes time to think, after which each has to correctly answer what hair color the wife has that is standing behind him, or lose his life. When you, as one of the three explorers, gain your sight after the blindfold comes off, you see two brunettes standing behind your two colleagues. And now your life depends on figuring out who is behind you: a blonde or a brunette?

Originally there were 3 brunettes and 2 blondes. If once you are able to see, you realize that 2 brunettes are standing behind your friends, that means that behind you there could be one of two blondes or the remaining brunette.

The possibility of the wife behind you being a blonde is 2/3 or 67%, while the chance of her being brunette is only 33%. But this question is not about probability, instead it is about game strategy. I would bet that the wife behind me is a brunette.

Imagine that the two women that you saw were blondes, then you would immediately say brunette. Even if you only saw one blonde wife, your obvious choice would be brunette. This applies to all 3 friends and the chief is gambling against you all 3. He will not give any of you any type of advantage.