In each of the following, f is a function from a set A to a set B. Determine whether f is one to one. Determine whether f is onto. Justify your conclusions.
a. A = {2, 3, 4}; B = {w, x, y, z}; f = {(2, x), (4, y), (3, w)}.
b. A = {1, 7, 0}; B = {a, b}; f = {(1, a), (7, b), (0, a)}.