The formula is 2number of elements in the set
This set {1,2,3} has 3 elements, so the number of subsets is gotten by
substituting 3 for the number of elements in the set:
2number of elements in the set = 23 = 2x2x2 = 8
So there are 8 subsets. They are
1. { } or ∅, the empty set, sometimes called the "null" set.
2. {1}
3. {2}
4. {3}
5. {1,2}
6. {1,3}
7. {2,3}
8. {1,2,3}
The last one is the entire set, which is considered to be a subset
of itself, although it is not considered to be a PROPER subset.
Edwin