If A = {1, {2, 3}}, find P(A) and n {P(A)}.
Let {2,3} = x
Now, A = {1,x}
Subsets of A are ϕ , {1} , {x} , {1,x}
⇒ Subsets of A are ϕ , {1} , {2,3} , {1, {2,3}}
Now, n{P(A)} = 2m , where m = n(A) = 2
⇒ n{P(A)} = 22 = 4