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Uncertain Knowledge and Reasoning: Quantifying Uncertainty and Bayes’s Rule. Thr

ID: 3667501 • Letter: U

Question

Uncertain Knowledge and Reasoning: Quantifying Uncertainty and Bayes’s Rule. Three prisoners, A, B, and C, are locked in their cells. It is common knowledge that one of them will be executed the next day and the others pardoned. Only the governor knows which one will be executed. Prisoner A askes the guard a favor: "Please ask the governor who will be executed, and then take a message to one of my friends B or C to let him know that he will be pardoned in the morning". The guard agrees, and comes back later and tells A that he gave the pardon message to B. What are A's chances/probability of being executed, given this information? What about C's chances/probability of being executed, given this information and assuming that C learned about B’s pardoning?

Explanation / Answer

As B gets Pardoned in the morning , than the probability of A getting executed are :

Total number of events = 2

1. A getting executed

2. C geting executed

Probability of an event( A getting executed)

                                    = Number of outcomes that makes an event / total number of outcomes

                                    = 1 / 2

                                   = 50 %

Probability of C getting executed is also the same = 1 / 2   or 50%