A sailor sails between two ports. At each port, he stays with a woman, both of whom want to have a child with him. The sailor is initially reluctant but changes his mind and tosses a coin to decide: if it’s a head, he will have a child with one and if it’s tail, with both. If heads come up, he will open up The Sailor’s Guide to Ports, and whichever port, out of the two, features earlier, he will choose the woman on that port.
If A is the son of the sailor, what is the probability that he is an only son?
We’ll go to the Bayes’ to find out the answer.
