Obvious, just confusing, or problematic?
A strange man flips a fair coin (in secret) every time his wife gives birth to a child. Until now the couple has 2 children, and the man has flipped 2 coins in accordance. One of the 2 children (a boy by the way) was born on a tuesday, the man tells us, and the corresponding coin (tossed on tuesday thus) was head side up. What is the probability (from our point of view) that both coins showed heads?
Important:
The answer which will pop up as the correct one might perhaps not be right. Perhaps it just seems the most acceptable one ... Please think and compare very carefully. The hint to "the tuesday-boy paradox" is by no means meant to mislead ...
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1 solution
The correct answer is 2 7 1 3 , the same as for the "tuesday-boy paradox" ( https://brilliant.org/wiki/bayes-theorem ) (Look for: A family has two children. Given that one of the children is a boy, and that he was born on a Tuesday, ...).
As for probability and randomness, there is no difference between the heads/tails outcome of coin tossing and the gender outcome of child birth (at least in the sense the latter should be interpreted in probability examples in general). Moreover, in this puzzle there is an exact parallel between both kinds of events.