Relations and Functions — Class 12 Maths Solution

exemplar objective MCQ NCERT Exemp.Q.30,Page 14
Question

The maximum number of equivalence relations on the set $A = \{ 1,2,3\}$are

  • (a) 1
  • (b) 2
  • (c) 3
  • (d) 5 ✓ Correct
Step-by-step Solution
Correct answer: option (d)

It is given that,, $A = \{ 1,2,3\}$

Now, number of equivalence relations as follows

${R_1} = \{ (1,1),(2,2),(3,3)\}$

${R_2} = \{ (1,1),(2,2),(3,3),(1,2),(2,1)\}$

${R_3} = \{ (1,1),(2,2),(3,3),(1,3),(3,1)\}$

${R_4} = \{ (1,1),(2,2),(3,3),(2,3),(3,2)\}$

${R_5} = \left\{ {(1,2,3) \Leftrightarrow A \times A = {A^2}} \right\}$

$\therefore$ Maximum number of equivalence

relation on the set $A = \{ 1,2,3\} = 5$

NCERT & Exemplar solution for CBSE Class 12 Mathematics, Relations and Functions. Curated by Sachin Sharma. Free for all students.