Question

write the power set of a if a is= set 1,2,3

Answer 1

For the set S = {1,2,3}

subsets with 0 elements: 0 (the empty set)

subsets with 1 element: {1}, {2}, {3}

subsets with 2 elements: {1,2}, {1,3}, {2,3}

subsets with 3 elements: S

Hence:

P(S) = {0, {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, S