EP 734 Jeff Altman, The Big Game Hunter explains how to answer another of those tricky brainteaser questions that hedge funds use.
Today I want to offer up another 1 of those "wonderful" hedge fund questions. There are different nicknames for this one, but I'm going to call it, "the truth teller and the liar." Here's the scenario. You walking down the hallway and see 2 doors with one guard in front of each door. The they both know the correct answer, but one always gives the correct answer and the other one always lies. You only have one question that you can ask. Who do you ask and how do you choose? Remember, only one question. Here's how to answer the question. The short version is, whatever answer you get, choose the opposite one. The reason for it is simple. Here's the answer the question one. Again, you choosing the opposite of what you were told. The question that you have to ask is, "if I ask the other guard which door to open, what would he tell me?" That's the question you want to pose in order to figure out the answer. If you ask the honest guard about what the other one would say, he knows that the guy is going to lie. The liar would tell you to go to the wrong door. Right? If you ask the longer the question, he is going to lie to you.. He is going to tell you the wrong answer. No matter what, you have to go to the opposite door of what you are told.