9. Solution. To get a complete collection, it is necessary that among the 9 coupons from Semy, there are 6 that Temy is missing. The probability of this is

$$
\frac{C_{6}^{6} \cdot C_{11}^{3}}{C_{17}^{9}}=\frac{3}{442} \approx 0.007
$$
Answer: approximately $0.007$.

## Grading Criteria

| Complete Solution | 3 points |
| :--- | :--- |
| Reasoning is correct, the necessary ratio or product of fractions is set up, but a computational error is made | 2 points |
| No solution or incorrect solution. | 0 points |