1. Find the union of each of the following pairs of sets: (i) X = {1, 3, 5} Y = {1, 2, 3} (ii) A = {a, e, i, o, u} B = {a, b, c} (iii) A = {x: x is a natural number and multiple of 3} B = {x: x is a natural number less than 6} (iv) A = {x: x is a natural number and 1 < x ≤ 5} B = {x: x is a natural number and 6 < x ≤ 10} (v) A = {1, 2, 3}, B = ϕ