Write down all the subsets of the following sets

Write down all the subsets of the following sets:
(i) {a}
(ii) {a, b}
(iii) {1, 2, 3}
(iv) Φ
Answer
(i) The subsets of {a} are Φ and {a}.
(ii) The subsets of {a, b} areΦ, {a}, {b}, and {a, b}.
(iii) The subsets of {1, 2, 3} areΦ, {1}, {2}, {3}, {1, 2}, {2, 3}, {1, 3}, and {1, 2, 3}
(iv) The subset of Φ is Φ.