Correct Answer - 1365
Set must contain minimum two elements, such that sum of smallest and largest element is 13.
If set contains smallest number 1 and largest number 12 then we can select other elements of subset from {2,3,..,12}.
So, number of subsets are `2^(10)`.
If set contains smallest number 2 and largest number 11 then we can select other elements of subset from {3,4,..,10}.
So, number of subsets are `2^(8)`.
Similarly, we have subsets `2^(6),2^(4),2^(2),2^(0)`.
So, total number of subsets `1+2^(2)+2^(4)+..+2^(10)=1365`
