Consider a set A with n elements. Similarly consider another set B with m elements. Then ‘AxB’ has a total of ‘mn’ elements. A relation from set A to set B will be a subset of ‘A×B’. The total number of subsets possible for the set ‘A×B’ is 2n(A×B) =2mn In the above question n is 3 and m is 4. Hence the total number of relations from B to A will be 2n(B×A) =2(4)(3) =212 =4096