Dse 2015 Doubt

[happy]

anyone plz

[Akki]

i did this using an example,
If S = {1,2,3}
then wrote all the subsets.
Since maximum no. of subsets have to be 2^m so, the given condition holds only for (b).

[happy]

S has n element . So the total no of subset of S = 2^n (NOT 2^m)

[Akki]

ohh sorry, i misread