$LetR=\{(a,b),(b,c)\}$ be a relation defined on, the set $A=\{a,b,c\}$The least number of ordered Pairs to be included in R so that it may be an equivalence relation on A is ­­­­­­­­­­­­­____________ .

For reflexivity we have to add $(a,a),(b,b)\text{\hspace{0.17em},}(c,c)$Then for symmetric relation, we have to add $(b,a)$

and  $(c,b)$ and $(c,b)$ Finally for transitive relation we have to add $(a,c)$ $(c,a)$ So atleast 7 ordered pairs should be included