213. Three heirs received 21 barrels: 7 - full, 7 - filled to half, and 7 - empty. Divide the inheritance so that each heir receives as much wine as barrels.

Problem from the manuscript collection "Problems for the Sharpening of the Mind."
213. Since each should have $3 \frac{1}{2}$ barrels of wine, it is clear that there are two solutions:

|  | $\\| \mathrm{y} 1-$ | $\sqrt{2-1}$ | $3-$ | $\sqrt{1-1}$ | $2-1$ | $3-\mathrm{r} 0$ |
| :---: | :---: | :---: | :---: | :---: | :---: | :---: |
| Full barrels . . . . .  ” half-full barrels  „empty barrels . . . . | 3  1  3 | 3  1  3 | 1  5  1 | 2  3  2 | 2  3  2 | 3  1  3 |