If there are 28 relation from a set A = {2,4, 6, 8} to a set B, then the number of elements in B is …
(1) 7
(2) 14
(3) 5
(4) 4
n(A) = 4
n(A x B) = 28
n(A) x n(B) = 28
4 x n(B) = 28
n(B) = 28/4 = 7
