Sets A and B have `3` and `6` elements each. The maximum possible number of elements in A-B is __________

Answer

To find the maximum possible number of elements in the set difference \( A - B \) (which represents the elements that are in set \( A \) but not in set \( B \)), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Elements in Sets**:
- Set \( A \) has 3 elements.
- Set \( B \) has 6 elements.

2. **Understand Set Difference**:
- The set difference \( A - B \) includes all elements that are in set \( A \) but not in set \( B \).

3. **Determine the Maximum Condition**:
- To maximize the number of elements in \( A - B \), we need to ensure that none of the elements of set \( A \) are present in set \( B \). This means that all elements in set \( A \) must be unique and not overlap with those in set \( B \).

4. **Calculate the Maximum Elements in \( A - B \)**:
- If there are no common elements between sets \( A \) and \( B \), then:
\[ A - B = A \]
- Since set \( A \) has 3 elements, the maximum possible number of elements in \( A - B \) is:
\[ |A - B| = |A| = 3 \]

5. **Conclusion**:
- Therefore, the maximum possible number of elements in \( A - B \) is **3**.