Q. Consider the following relations from A to B where A = {u, v, w, z} and B= {p, q. r, s}.
1. {(u. p), (v, p), (w, p), (x, q), (y, q), (z, q)}
2. {(u, p), (v, q), (w, r), (z, s)}
3. {(u, s), (v, r), (w, q), (u, p), (v, q), (z, q)}
4. {(u, q), (v, p), (w, s), (x, r), (y, q), (z, s)}
Which of the above relations are not functions ?