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Let R be a non-empty relation on a collection of sets defined by ARB if and only if A ∩ B = Ø Then (pick the TRUE statement)

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Let R be a non-empty relation on a collection of sets defined by ARB if and only if A ∩ B = Ø Then (pick the TRUE statement)
  • AR is relexive and transitive
  • BR is an equivalence relation
  • CR is symmetric and not transitive
  • DR is not relexive and not symmetric
Correct answer: C
0
CCommunity
R is symmetric and not transitive

R is symmetric and not transitive
0
CCommunity
Note here, it’s written that the relation is on collection of sets, i.e. the relation is between sets not between elements of sets. So, (A,B) will be part of R iff A∩B = ∅.



So it cant be reflexive since A∩A != ∅



But it can be symmetric since A∩B = B∩A = ∅ (here A and B are disjoint sets, A={1,2} and B={3,4}



Also, its not sure that it will always be transitive, for eg. A={1,2}, B={3,4} and C={2,5}, here A∩B = ∅, B∩C = ∅ but A∩C != ∅



which makes R, symmetric but not reflexive or transitive.