Question

If A = {1,2,3,4} and B = {x,y}, then find the total number of relations between A and B.
(2 marks)

Answer 1

We know that, if n(A) = p, n(B) = q then, total number of relations between A and B is 2${}^{\text{pq}}$ (1 mark)
Here, n(A) = 4, n(B) = 2
$\therefore$Total number of relations from A to B = 2${}^{(4\times 2)}$
= 2${}^8$
= 256 (1 mark)