In following question use ( notation to indicate which set is a subset of the other.
1. C = {a, b, 1, 2, 3} and D = {a, b, 1}
2. E = {x, y, a, b}, F = {x, 1, a, y, b, 2}
3. A = {6, 8, 7, 4}, B = {8, 7, 6, 4}
4. D = {a, e, 1, 3, c}, F = {e, a, c, 1, 3}