6
The empty set has only one subset: itself. It has no proper subsets.
6
It depends on the set x. If set x is of cardinality n (it has n elements) then it has 2n subsets.
There are 6 such subsets of B.
6
An element doesn't have subsets. Sets can have subsets.
512 subsets
8 subsets
A set with 9 elements has 2^9 = 512 subsets.
A set with 50 elements has 250 subsets.
A set with N elements has 2N subsets.
To find how many proper subsets there are in a set you can use the formula n^2 -n and if you would also like to find all subsets including improper the formula is n^2 -n +1
7.
If the universal set contains N elements then it has 2N subsets.
The empty set has only one subset: itself. It has no proper subsets.
If you have a set of 6 elements, you can make a total of 26 different subsets - including the empty set and the set itself.