(10 elements..........) 2^(10)=1024 A discrete set with n elements has 2^n subsets. 2^n=1024 implies there are n=10 elements in this set. Any subset with 0 through n-1 elements is a proper subset of the set, as in each of those cases there exists at least one element of the set that is not in the subset, which is the requirement to be a proper subset. Therefore, we have 1023 proper subsets.
The above answer is wrong because he mis read the question it seems. It is asking for the element, not mores subsets. The answer is 10 elements, i did this on my assignment and got it right.
