Let A and B be two sets such that n(A) = 5, n(B) = 3 and n(A ∩ B) = 2.
(i) n(A ∪ B)
(ii) n(A × B)
(iii) n(A × B) ∩ (B × A)
(i) n(A ∪ B) = n(A) + n(B) - n(A ∩ B)
= 5 + 3 – 2
=6
(ii) n(A × B) = n(A) × n(B)
= 5 × 3
= 15
(iii) n(A × B) ∩ (B × A) = n(A × B) + n(B × A) –