Question

how many elements has P(A), if A = fie..?

Answer 1

If A contains m no. of elements, then,
n(A)=m and n[P(A)]=2^m
Here,A= fie then,
n(A)=0 as any set having fie as the only element is considered as null set.
So,
n[P(A)]=2^m i.e., n[P(A)]=2^0
=> n[P(A)]=1
Therefore, there is only one element in power set of A.