We can solve this problem using definition of power set. Power set: The set of all subsets of a given set A is called the power set of A and is denoted by P(A). Example: If A = {1, 2, 3}, then P(A) = {∅ ,{1},{2},{3},{1,2},{1,3},{2,3} ,{1,2,3}} clearly, if A has n elements ,then its power set P(A) contains exactly 2n elements. By using this definition of power set, we can find the answer. We have P(A) = Powerset of A n(A) = m We know that The set of all subsets of a given set A is called the power set of A and is denoted by P(A). n[P(A)] = total no: of possible subset of A ie, n[P(A)] = 2m Therefore, Let P(A) denote the power set of A. If n(A) = m then n[P(A)] = 2m