Q. Let $R=\{(1,2),(2,3),(3,3)\}$ be a relation defined on the set $\{1,2,3,4\}$. Then the minimum number of elements, needed to be added in $R$ so that $R$ becomes an equivalence relation, is:

A) 10
B) 7
C) 8
D) 9
Explanation

[Solution by Dr. Abubacker] An equivalence relation containing $(1,2)$ and $(2,3)$ must link $1,2,3$ into one class: all $3\times3=9$ pairs, plus $(4,4)$ for reflexivity, giving 10 elements. $R$ already has 3 of them, so $10-3=7$ must be added. Answer (2).

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.

Want to attempt the full paper?
View Full Paper Take Full Paper Online