Set difference A − B with small numeric sets: Let A = {1, 2, 3, 4, 5} and B = {2, 4, 6}. Find A − B (elements in A that are not in B).

Introduction / Context:
Set difference A − B collects items that belong to A but not to B. It is a fundamental operation in set theory and appears frequently in data filtering and logic puzzles.

Given Data / Assumptions:

• A = {1, 2, 3, 4, 5}
• B = {2, 4, 6}

Concept / Approach:
Remove from A every element that appears in B. Elements 2 and 4 are common and are excluded from A − B.

Step-by-Step Solution:
Start with A: {1, 2, 3, 4, 5}Remove 2 and 4 (present in B)Result: {1, 3, 5}

Verification / Alternative check:
Symmetric difference would include 2 and 4 differently, but set difference strictly excludes A’s elements present in B.

Why Other Options Are Wrong:
{2, 3, 5} and {1, 4, 5} keep elements that should be removed; {2, 3, 6} includes 6, which is not in A.

Common Pitfalls:
Confusing A − B with B − A or with symmetric difference.

Final Answer:
{1, 3, 5}