10 10 votes Consider the poset $( \{3,5,9,15,24,45 \}, \mid).$ Which of the following is correct for the given poset ? There exist a greatest element and a least element There exist a greatest element but not a least element There exist a least element but not a greatest element There does not exist a greatest element and a least element Set Theory & Algebra ugcnetcse-june2019-paper2 poset set-theory&algebra + – Arjun 9.5k views answer comment Share Follow Print 0 reply Please log in or register to add a comment.
Best answer 9 9 votes There are two maximal elements $24$ and $45$. There are two minimal elements $5$ and $3$. So there is no greatest and least element. $\therefore$ Option $4.$ is correct. Satbir answered Jul 3, 2019 • edited Jul 23, 2019 by Lakshman Bhaiya Satbir comment Share Follow See all 2 Comments 2 2 Comments reply Arjun commented Jul 8, 2019 reply Follow flag Can there ever be two greatest elements? 0 0 replyShare Satbir commented Jul 8, 2019 reply Follow flag No....because we can't compare them. there can be many maximal elements but only one maximum element. 3 3 replyShare Please log in or register to add a comment.
4 4 votes 1-We can not choose here greatest element because two maximal element(24,45 are at same level in Hasse diagram) are there. 2-We can not choose here least element because two minimal element(3,5 are at same level in Hasse diagram) are there. So: Option 4 is correct. Arnabh Gangwar answered Jul 8, 2019 • edited Jul 8, 2019 by Arnabh Gangwar Arnabh Gangwar comment Share Follow 0 reply Please log in or register to add a comment.
–1 –1 vote C is correct answer because there exists LCM(A,B) FOR all a,b belongs to the set bhupendrakumar answered Sep 4, 2019 bhupendrakumar comment Share Follow 0 reply Please log in or register to add a comment.