The number of non-empty equivalence relations on the set {1, 2, 3} is: [2025]
5
6
7
4
(1)
Partitions of set {1, 2, 3} is {{1}}, {2}, {3}}, {{1, 2}, {3}}, {{1, 3}, {2}}, {{2, 3}, {1}}, {{1, 2, 3}}
∴ Number of non-empty equivalence relations on the set {1, 2, 3} = 5.