Question

Let U = {1, 2, 3, 4, 5, 6}, A = {2, 3} and B = {3, 4, 5}. Find A’, B’, A’ ∩ B’,(A ∪ B) and hence show that (A ∪ B)’ = A’ ∩ B’.

Answer 1

A’ = ∪ - A = { 1,4,5,6}

B’ = U - B = { 1,2,6}

A’ ∩ B’ = {1,6}

A ∩ B = {2,3,4,5}

∴ (A ∪ B)’ = {1, 6} = A’ ∩ B’