0 votes 0 votes Suppose that a set S has n elements. How many ordered pairs(A,B) are there such that A and B are subsets of S with A$\subseteq$ B? Combinatory kenneth-rosen discrete-mathematics combinatory + – aditi19 asked Nov 14, 2018 edited Mar 4, 2019 by Pooja Khatri aditi19 504 views answer comment Share Follow See 1 comment See all 1 1 comment reply Shiva Sagar Rao commented May 28, 2021 reply Follow Share https://gateoverflow.in/4580/suppose-that-with-elements-ordered-pairs-there-subsets-with https://gateoverflow.in/18496/tifr2010-a-18 0 votes 0 votes Please log in or register to add a comment.
1 votes 1 votes Each element can either be (1) in neither A nor B, (2) in only B, (3) in both A and B, there are total n element and each element have 3 choice so total order pair 3n Gurdeep Saini answered Nov 14, 2018 Gurdeep Saini comment Share Follow See all 5 Comments See all 5 5 Comments reply Show 2 previous comments aditi19 commented Nov 14, 2018 reply Follow Share why are you considering {{1,},{1,2}} as ordered pair? 0 votes 0 votes Gurdeep Saini commented Nov 14, 2018 reply Follow Share We have to make the order pair of subset ,read the question again 0 votes 0 votes aditi19 commented Nov 15, 2018 reply Follow Share oh i got it now.. thank u :) 0 votes 0 votes Please log in or register to add a comment.