3. Establish the rule according to which the table is constructed, and fill in the missing numbers:

| 9 | 81 | 2 |
| :---: | :---: | :---: |
| 16 | 256 | 2 |
| 11 | 11 |  |
| 6 | 216 | 3 |
| 5 |  | 3 |
3. Since $9^{2}=81,16^{2}=256,6^{3}=216$, the numbers in the middle column are powers, the left column contains their bases, and the numbers in the right column are the exponents. Therefore, the number 1 is missing in the right column, and in the middle column, $125\left(5^{3}=125\right)$.