Write down all the subsets of the following sets.
(i) {a} (ii) {a, b} (iii) {1, 2, 3} (iv) ϕ.
(i) Number of elements in given set = 1
Number of subsets of given set = 21=2
∴ Subsets of given set are ϕ, {a}.
(ii) Number of elements in given set = 2
Number of subsets of given set = 22=4
∴ Subsets of given set are ϕ, {a}, {b}, {a, b}.
(iii) Number of elements in given set = 3
Number of subsets of given set = 23=8
∴ Subsets of given set are ϕ, {1}, {2}, {3}, {1, 2}, {2, 3} {1, 3}, {1, 2, 3}.
(iv) Number of elements in given set = 0
Number of subsets of given set = 20=1
∴ Subset of given set is ϕ.