Given two sets A and B, the intersection of sets A and B (denoted as A ∩ B) is the set of elements belonging to both sets A and B (the set of elements they have in common).

N: The natural numbers

A: {1, 2, 3, 4, 5, 6}

B: {3, 4, 5, 6, 7, 8, 9, 10}

A ∩ B: {3, 4, 5, 6}

N: The natural numbers

A: {1, 2, 3, 4, 5}

B: {6, 7, 8, 9, 10}

A ∩ B: Φ

N: The natural numbers

A: {4, 5, 6}

B: {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

A ∩ B: {4, 5, 6}

Note for this example that A ∩ B = A

Q: The rational numbers

N: The natural numbers

W: The whole numbers

N ∩ W = N