Question

Let A = {1, 2, 3} , B = {2, 3, 4} , then n[(A*B)intersection (B*A)]= ? where * means multiply
A. 1
B. 2
C. 3
D. 4​

Answer 1

n(AB)=(2,3)

n(BA)=n(AB)

i.e n(BA)=(2,3)