A and B are disjoint sets and n(A)=6, number of elements in the union of the power sets of A and B is 71 find n(a union b)

Question

N(a) represents the no. Of elements in set a 

Answer 1

The empty set appears in both power sets.

So do the original sets.

 

That knocks the total down to 68 UNIQUE elements.

 

Since n(A) = 6, it has 2^6 = 64 elements in the power set.

 

So B has 4 = 2^N elements in the power set

N=2