2 votes 2 votes Set Theory & Algebra no-of-topological-ordering + – Lakshman Bhaiya asked Dec 25, 2017 Lakshman Bhaiya 1.9k views answer comment Share Follow See all 16 Comments See all 16 16 Comments reply Ashwin Kulkarni commented Dec 25, 2017 i edited by Ashwin Kulkarni Dec 25, 2017 reply Follow Share is it 38? 0 votes 0 votes Lakshman Bhaiya commented Dec 25, 2017 reply Follow Share No Right is 48 but I don't know how 0 votes 0 votes Ashwin Kulkarni commented Dec 25, 2017 reply Follow Share There is no particular formula, I got 38 cases by applying different combinations! don't know which am I missing? 0 votes 0 votes rahul sharma 5 commented Dec 25, 2017 i edited by rahul sharma 5 Dec 26, 2017 reply Follow Share I got 60 H - - - - - - A Six places to fill d depend e and g,(egd,ged) bc depend on f (bcf,cbf) So total 2 choices for deg and 2 for bcf. Now select 3 positions out of 6 and place egd in 2 ways and remaining fbc can be placed in two ways. $C(6,3)*2 *C(3,3)*2 = 80$ I think this has been asked earlier but i am not able to find.What is the source of this question?Can someone check if 80 is the answer or 48? 0 votes 0 votes Lakshman Bhaiya commented Dec 26, 2017 i edited by Lakshman Bhaiya Dec 26, 2017 reply Follow Share You can see this answer 0 votes 0 votes Ashwin Kulkarni commented Dec 26, 2017 reply Follow Share I did the same way :( just missed two cases :( 0 votes 0 votes rahul sharma 5 commented Dec 26, 2017 reply Follow Share @Ashwin,why 60 is not correct? What extra did i count? 0 votes 0 votes raj_rajvir commented Dec 26, 2017 reply Follow Share Which test-series is this ? 0 votes 0 votes raj_rajvir commented Dec 26, 2017 reply Follow Share @lakshman patel rjit hfegbdca is also a topological ordering. Right ? then in which case of the above explanation is it covered ? 0 votes 0 votes raj_rajvir commented Dec 26, 2017 reply Follow Share @rahul sharma You have made a calculation mistake. 6C3 * 2 * 3C3 * 2 = 80 0 votes 0 votes Lakshman Bhaiya commented Dec 26, 2017 reply Follow Share @raj_rajvir Testbook 0 votes 0 votes rahul sharma 5 commented Dec 26, 2017 reply Follow Share @raj thanks. I have updated.What answer are you getting? 0 votes 0 votes raj_rajvir commented Dec 26, 2017 reply Follow Share @rahul sharma 5. same answer. Btw can you guys suggest some good test series such that I can have a good evaluation of where I stand relative to others and also the quality of questions is good 0 votes 0 votes Lakshman Bhaiya commented Mar 19, 2018 reply Follow Share Please explain anyone in a more clear way?? 0 votes 0 votes Dharmendra Lodhi commented Sep 7, 2018 reply Follow Share https://gateoverflow.in/240811/topological-sort 0 votes 0 votes Dharmendra Lodhi commented Sep 7, 2018 i edited by Lakshman Bhaiya Dec 26, 2018 reply Follow Share https://gateoverflow.in/240811/topological-sort 0 votes 0 votes Please log in or register to add a comment.