Question

Let A = {1,2} and B = {3,4}. Find the number of relations from A to B.

Answer 1

Given, A = {1,2} and B = {3,4}.

Number of elements in set A = $n\left(A\right)=2$

Number of elements in set B = $n\left(B\right)=2$

Number of relations from A to B = $2^{n\left(A\right)\times n\left(B\right)}$

$=2^{2\times 2}=2^4=16$