Question

Find A ∪ B, A ∩ B, A – B and B – A for the following sets

A = {x : x ∈ N, x ≤ 10} and B = {x : x ∈ W, x < 6}

Answer 1

x ∈ {1, 2, 3, ……..}; x ∈ {0, 1, 2, 3, 4, 5, ……..}

A = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} and B = {0, 1, 2, 3, 4, 5}

A ∪ B = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} ∪ {0, 1, 2, 3, 4, 5}

= {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

A ∩ B = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} ∩ {0, 1, 2, 3, 4, 5}

= {1, 2, 3, 4, 5}

A – B = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} – {0, 1, 2, 3, 4, 5}

= {6, 7, 8, 9, 10}

B – A = {0, 1, 2, 3, 4, 5} – {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

= {0}