1 votes 1 votes Let S = {1, 2,......,10 }. The number of unordered pairs A, B where A and B are disjoint non-empty subsets of S is _________ (counting unordered pairs simply means we don’t distinguish the pair A,B and B,A) Mathematical Logic discrete-mathematics set-theory&algebra combinatory + – indrajeet asked Feb 1, 2017 • retagged Jun 27, 2017 by Arjun indrajeet 381 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.