Mathematics · Sets and Relations

JEE Main 2024 — 27 January, Shift 1 — Question 10

Let S={1,2,3,…,10}S=\{1,2,3, \ldots, 10\}. Suppose MM is the set of all the subsets of SS, then the relation R={(A,B):A∩B≠ϕ;A,B∈M}R=\{(A, B): A \cap B \neq \phi ; A, B \in M\} is :

  1. Option A:

    symmetric and reflexive only

  2. Option B:

    reflexive only

  3. Option C:

    symmetric and transitive only

  4. Option D:

    symmetric only

    Correct

Answer: D

Step-by-step solution

Let S={1,2,3,…,10}\mathrm{S}=\{1,2,3, \ldots, 10\}

R={(A,B):A∩B≠ϕ;A,B∈M}\mathrm{R}=\{(\mathrm{A}, \mathrm{B}): \mathrm{A} \cap \mathrm{B} \neq \phi ; \mathrm{A}, \mathrm{B} \in \mathrm{M}\}

For Reflexive, M is subset of ' S ' So ϕ∈M\phi \in \mathrm{M}

for ϕ∩ϕ=ϕ\phi \cap \phi=\phi ⇒\Rightarrow

but relation is A∩B≠ϕ\mathrm{A} \cap \mathrm{B} \neq \phi

So it is not reflexive. For symmetric, ARB A∩B≠ϕ\quad \mathrm{A} \cap \mathrm{B} \neq \phi

⇒BRA⇒B∩A≠ϕ\Rightarrow \mathrm{BRA} \quad \Rightarrow \mathrm{B} \cap \mathrm{A} \neq \phi,

So it is symmetric. For transitive, If A={(1,2),(2,3)}\mathrm{A}=\{(1,2),(2,3)\}

B={(2,3),(3,4)}B=\{(2,3),(3,4)\} C={(3,4),(5,6)}\mathrm{C}=\{(3,4),(5,6)\}

ARB & BRC but A does not relate to C So it not transitive

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Sets and Relations
Topic
Types of Relations
Let S=\ 1,2,3, ldots, 10\ . Suppose M is the set of all the subsets… | JEE Main 2024 PYQ with Solution · DhiX AI