0 votes 0 votes My explanation I have provided, Please rectify the mistake where I am going wrong :) HeadShot asked Jul 13, 2018 HeadShot 866 views answer comment Share Follow See all 4 Comments See all 4 4 Comments reply HeadShot commented Jul 13, 2018 reply Follow Share Please correct me where I am going wrong , Thank you :) 0 votes 0 votes srestha commented Jul 13, 2018 reply Follow Share Ans 27? 0 votes 0 votes HeadShot commented Jul 13, 2018 i edited by HeadShot Jul 13, 2018 reply Follow Share @ srestha They have provided ans as option ( D) Will you explain the approach please. 0 votes 0 votes Shaik Masthan commented Jul 13, 2018 reply Follow Share i hope this images helps 1 votes 1 votes Please log in or register to add a comment.
Best answer 2 votes 2 votes Option d is right abhishekmehta4u answered Jul 13, 2018 • selected Jul 13, 2018 by HeadShot abhishekmehta4u comment Share Follow See all 17 Comments See all 17 17 Comments reply gauravkc commented Jul 13, 2018 reply Follow Share Why 3n(n-1)/2 ? 0 votes 0 votes HeadShot commented Jul 13, 2018 reply Follow Share @ abhishekmehta4u Thank a lot ! Can you please explain : 1. # neither reflexive nor irreflexive 0 votes 0 votes HeadShot commented Jul 13, 2018 reply Follow Share @gauravkc Hope this will help. 3 votes 3 votes gauravkc commented Jul 13, 2018 reply Follow Share Thanks :) 0 votes 0 votes HeadShot commented Jul 13, 2018 reply Follow Share @abhishekmehta4u Is this a correct approach for "neither...nor " question I asked ? Like, 1 (a,a) pair must be rejected so that it will not be reflexive, and 1 should be kept so that it wont he irreflexive. Way of doing this is " 1st term or 2nd term " as shown in fig. Please correct me if I am wrong . 0 votes 0 votes abhishekmehta4u commented Jul 13, 2018 reply Follow Share @Headshot.. 2 votes 2 votes HeadShot commented Jul 13, 2018 reply Follow Share @ abhishekmehta4u Wow... Very nice explanation... cleared my most of the concepts. I solved remaining problems because of your help... Great help. Thank you so much :) 1 votes 1 votes HeadShot commented Jul 13, 2018 reply Follow Share @ abhishekmehta4u Will you please check my method, I guess it is working too (I calculated for n= 4 ) so that I ll get to know it is valid way or not. P.S : Last term is 2^1 insted of 2^(n-n) . I realized its 2^[n-(n-1)] . Please ans if possible, it will be really helpful. Thanks :) 1 votes 1 votes abhishekmehta4u commented Jul 13, 2018 reply Follow Share can you explain little bit more . i can not understand ur logic?? 0 votes 0 votes srestha commented Jul 13, 2018 reply Follow Share @ abhishekmehta4u formula for antisymmetric relation $3^{\frac{n^{2}-n}{2}}.2^{n}$ where $2^{n}$ is for reflexive relation or we can also say antisymmetric relation without reflexive relation is asymmetric right? Isnot then answer incorrect? 0 votes 0 votes abhishekmehta4u commented Jul 13, 2018 reply Follow Share Antisymmetric relation without reflexive relation is asymmetric. No its not correct. S={1,2,3} R={(1,2)(2,3)(1,1)}--->it is antisymm ant not reflexive nor asymmetric. 2 votes 2 votes HeadShot commented Jul 13, 2018 reply Follow Share @ abhishekmehta4u I thought over it again, but I missed a point.. The image below is what I want to convey, now I corrected it but it is not giving the answer.. Will you analyze it once and see if its somewhere close..not as a solution but approach and tell where my concept going wrong. After satisfying both the conditions , i think it doesnt matter whether we select one pair or (+) two pairs or (+) and so on... Thats why there are additions in above expression. Still I am not sure whether I am conveying it in right way or not but have a look , it will surely help me . Thank you :) 0 votes 0 votes HeadShot commented Jul 13, 2018 reply Follow Share @ abhishekmehta4u Will it be fine if i say ... " Antisymmetric with irreflexivity is assymetric " ? 0 votes 0 votes srestha commented Jul 13, 2018 reply Follow Share Antisymmetric with irreflexivity is assymetric yes true. because definition of irreflexive is A relation on a set is irreflexive provided that no element is related to itself; in other words, for no in So, not reflexive different from irreflexive 0 votes 0 votes gauravkc commented Jul 14, 2018 reply Follow Share But if the set has numbers from 1 to n (Say) For a relation to be reflexive, all (x,x) for x=1..n should be in relation. Any one of them missing in relation will make it irreflexive. However, in asymmetric, there should be no (x,x) relation. So I guess we cannot say that. Please correct me if I'm wrong. 0 votes 0 votes srestha commented Jul 14, 2018 reply Follow Share but definition of irreflexive is No $\left ( x,x \right )$ element will be present there Any $\left ( x,x \right )$ is present then it is not irreflexive and nor even reflxive right? 0 votes 0 votes gauravkc commented Jul 14, 2018 reply Follow Share Oops, my mistake. Sets who contain at least all (x,x) pairs are reflexive Sets who do not contain any (x,x) pair are irreflexive Sets who have few (x,x) pairs are neither reflexive nor irreflexive 0 votes 0 votes Please log in or register to add a comment.