Number of subsets of a set = 2^{n}

where n is the number of elements of the set

**For set A = {1, 2}**

The subsets are ∅, {1}, {2}, {1, 2}

So, Number of subsets = 2^{2} = 4

Similarly,

**For B = {1, 2, 3}**

Subsets will be

∅,

{1}, {2}, {3},

{1, 2}, {2, 3}, {1, 3},

{1, 2, 3}

So, Number of subsets = 2^{3} = 8

## Number of elements of power set

Now,

We know that power set is the set of all subsets.

∴ Number of elements of power set = Number of subsets of set

Number of elements of power set = 2^{n}