In each case below a relation between set S and set T is described. In each case explain why the relation is not a function from the set S to the set T. (a) S is the set of ordered pairs of integers (Z×Z) and T = Q is the set of rational numbers. An ordered pair of integers s = (n, m) and a rational number t are related if t = n/m. (b) S is the set of all California license plates in California and T = N. A license plate s ∈ S is related to t ∈ N when t is the smallest number that appears in the license plate number on s. (c) S = R is the set of real numbers and T is the set of ordered pairs of real numbers (R×R). A real number s is related to the ordered pair of real numbers t = (x, y) if s = x + y.