Let $A = \{1, 2, 3\}$. The number of relations on $A$, containing $(1,2)$ and $(2,3)$, which are reflexive and transitive but not symmetric, is ___
Let $A=\{2,3,6,7\}$ and $B=\{4,5,6,8\}$. Let $R$ be a relation defined on $A\times B$ by $(a_1,b_1)\,R\,(a_2,b_2)$ if and only if $a_1+a_2=b_1+b_2$. Then the number of elements in $R$ is _____
Let $X = \mathbb{R} \times \mathbb{R}$. Define a relation $R$ on $X$ as: $(a_1, b_1)\,R\,(a_2, b_2) \Leftrightarrow b_1 = b_2$. Statement I: $R$ is an equivalence relation. Statement II: For some $(a,b) \in X$, the set $S = \{(x,y) \in X : (x,y)\,R\,(a,b)\}$ represents a line parallel to $y = x$. Choose the correct option:
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:
Let $A=\{1,3,4,6,9\}$ and $B=\{2,4,5,8,10\}$. Relation $R=\{((a_1,b_1),(a_2,b_2)):\ a_1\leq b_2\ \text{and}\ b_1\leq a_2\}$ has how many elements?