The maximum number of equivalence relations on the set $A = \{ 1,2,3\}$are
- (a) 1
- (b) 2
- (c) 3
- (d) 5 ✓ Correct
The maximum number of equivalence relations on the set $A = \{ 1,2,3\}$are
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 $A = \{ 1,2,3\} = 5$
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