Consider the following relation Demo:
| ID | name | salary |
| 1 | A | 65000 |
| 2 | B | 90000 |
| 3 | C | 40000 |
| 4 | D | 95000 |
| 5 | E | 60000 |
| 6 | F | 87000 |
| 7 | G | 75000 |
| 8 | H | 62000 |
| 9 | I | 80000 |
| 10 | J | 72000 |
| 11 | K | 92000 |
| 12 | L | 80000 |
The number of tuples returned for the query \(Π_{salary} (Demo)-Π_{Demo.salary} (σ_{Demo.salary
Enter numerical value using the virtual keypad. Round off where necessary.