Puzzle 7a. I have two children, of whom at least one is a boy. Their names are Alex and Sam. (In this fictional puzzle, these names communicate no information about gender.) Alex is a boy. What is the probability that Sam is a boy?
Puzzle 1a. I have two children, of whom at least one is a boy. Now I shall toss a coin and accordingly choose one of the two children. (Does so.) The child I chose is a boy. What is the probability that the other is a boy?
Puzzle 7a. I have two children, of whom at least one is a boy. Their names are Alex and Sam. (In this fictional puzzle, these names communicate no information about gender.) Alex is a boy. What is the probability that Sam is a boy?
Puzzle 1a. I have two children, of whom at least one is a boy. Now I shall toss a coin and accordingly choose one of the two children. (Does so.) The child I chose is a boy. What is the probability that the other is a boy?