9 Which are the numbers between 81 and 111 that are divisible by 2 ?

Step 1 ：\(a = \lceil \frac{81}{2} \rceil = 41\)

Step 2 ：\(b = \lfloor \frac{111}{2} \rfloor = 55\)

Step 3 ：\(2 \cdot i\), \(i \in \{41, 42, ..., 55\}\)