The Widow's Estate and the Stranger's Share
A woman dies leaving a husband, a son, and three daughters, and a will that bequeaths a stranger exactly 1/8 plus 1/7 of her whole estate. By the inheritance law of the time, the husband then takes a quarter of whatever remains, and each son must receive exactly twice what each daughter receives. If the estate is worth 224,000 dirhams, how much does each person get?
Reveal the answer
The stranger gets 15/56 of the estate (60,000); of the 41/56 left, the husband takes a quarter (41,000); the remaining 123,000 splits 2:1:1:1, so the son gets 49,200 and each daughter gets 24,600. This is one of dozens of worked inheritance cases in al-Khwarizmi's 9th-century Al-Jabr — the book that gave algebra its name, with over half of it devoted to solving Islamic inheritance-law splits as linear equations.