Question

Let A = {(n, 2n) : n ∈ z} and B = {(2n , 3n) : n ∈ z)}, what is A ∩ B equal to

(a) {(n, 6n) : n ∈ z}

(b) {(2n , 6n) : n ∈ z}

(c) {(n , 3n) : n ∈ z}

(d) φ

Answer 1

Correct option is (d) φ

A = (n, 2n) ; n ϵ Z

B = (2n, 3n) ; n ϵ Z

A ∩ B = φ (there is no ordered pair).