Ketubot, Chapter Ten, Mishnah Four
This mishnah discusses a man who married three women at the same time, and gave one of them a ketubah worth one maneh (100 zuz), the second a ketubah worth 200 and the third a ketubah worth 300. When he dies, and does not leave enough to cover all three, the question is how do they divide up his estate.
I am explaining this mishnah according to Albecks explanation, who uses R. Saadiah Gaons explanation to the mishnah as his basis. The Talmud offers a different, more complicated explanation.
1) If a man who was married to three wives died, and the kethubah of one was a maneh, and of the other two hundred zuz, and of the third three hundred zuz and the estate [was worth] only one maneh they divide it equally.
2) If the estate [was worth] two hundred zuz [the woman whose ketubah] is a maneh receives fifty zuz [and the woman whose ketubah] was two hundred and [the woman whose ketubah] was three hundred [receive each] three gold denarii (=seventy-five zuz).
3) If the estate [was worth] three hundred zuz, [the woman whose ketubah] was a maneh receives fifty zuz and [the woman whose ketubah] was two hundred [receives] a maneh and [the woman whose ketubah] was worth three hundred [receives] six gold denarii (=one hundred and fifty zuz).
4) Similarly, if three persons contributed to a joint fund and the fund lost or gained they share in the same manner.
The general rule is that any maneh (100 zuz) that is responsible for all three Ketubot, they divide equally. In our case, 100 zuz is responsible for all three, because all three have at least one maneh of a ketubah. Any maneh that is not responsible for all of the Ketubot is divided according to the percentage that they deserve from the total amount of ketubah money the man owes. In our case the total amount is 600 zuz; the first woman owns 1/6, the second 1/3 and the third 1/2. This shall be illustrated as we proceed.
Section one: If the estate was worth only one maneh, each woman has an equal right to this maneh. This is because the maneh is responsible for all three Ketubot. Therefore they divide it equally.
Section two: If the estate was worth 200, the first maneh is divided equally, as above. The second maneh is not responsible for all three Ketubot, hence it is not divided equally but rather by percentages. The first woman takes 1/6 of 100, leaving her with a total of 50 zuz. There is now 150 zuz left, all of which is subject to the Ketubot of the second and third widows. Therefore it is divided equally, both women taking 75 zuz.
Section three: In this case all three divide according to their percentages. The first woman takes 1/6 which is 50 zuz, the second woman takes 1/3 which is 100 zuz, and the third woman takes 150 zuz, which is 1/2. In such a scenario, each woman takes one-half of her ketubah. [Note that this division seems to work according to a different system from the previous two clauses.]
Section four: If three or more people invest together, each investing a different percentage, when they divide up the profits or losses, they are divided in the same manner.