kinship puzzles

Like age puzzles, problems to do with how family members are related go back many centuries. Some of these can be fiendishly convoluted, especially if incestual pairings are allowed (in the puzzle!). Sketching a genealogical tree is sometimes helpful. The following all involve legitimate ties:

Brothers and sisters have I none, but that man's father is my father's son. Who is that man? (This is one of the oldest problems of the kinship variety.)
What is the simplest way in which two people can be an uncle to each other? (From Dudeney's A Puzzle-Mine)
A certain family party consisted of 1 grandfather, 1 grandmother, 2 fathers, 2 mothers, 4 children, 3 grandchildren, 1 brother, 2 sisters, 2 sons, 2 daughters, 1 father-in-law, 1 mother-in-law, and 1 daughter-in-law. Twenty-three people, you will say. No; there were only seven persons present. Can you show how this might be? (From Amusements in Mathematics.)

Solutions

Your son.
Sons of two men who married each other's mothers.
The party consisted of 2 girls and a boy, their father and mother, and their father's father and mother.

Related categories

• GAMES AND PUZZLES
• TIME MEASUREMENT AND PUZZLES

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Encyclopedia of Alternative Energy & Sustainable Living
Encyclopedia of History

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