Let $A=\{2,3,4\}$, $B=\{8,9,12\}$. Let $R=\{((a_1,b_1),(a_2,b_2)):\ a_1|b_2\ \text{and}\ a_2|b_1\}$. Number of elements in $R$ is
Let $A=\{1,2,3,4,5\}$ and $B=\{1,2,3,4,5,6\}$. Then the number of functions $f:A\to B$ satisfying $f(1)+f(2)=f(4)-1$ is equal to........
Let P(S) denote the power set of S = \{1, 2, 3, \ldots, 10\}. Define the relations R_1 and R_2 on P(S) as: A R_1 B if (A \cap B^c) \cup (B \cap A^c) = \varnothing, and A R_2 B if A \cup B^c = B \cup A^c, for all A, B \in P(S). Then:
Given X = \{ n \in \mathbb{N} : 1 \leq n \leq 50 \}, A = \{ n \in X : n \text{ is multiple of } 2\} = \{2, 4, 6, 8, \ldots, 50\}, and B = \{ n \in X : n \text{ is multiple of } 7\} = \{7, 14, 21, 28, 35, 42, 49\}. Find the smallest subset of X containing elements of both A and B.
Let $A=\{0,3,4,6,7,8,9,10\}$ and $R=\{(x,y):\ x-y\text{ is odd positive}\text{ or }x-y=2\}$. Minimum elements to add to $R$ for it to be symmetric is equal to _________
Let $R=\{a,b,c,d,e\}$ and $S=\{1,2,3,4\}$. Total number of onto functions $f:R\to S$ such that $f(a)\neq1$ is equal to ________.
Let the relation $R$ on the set $M=\{1,2,3,\ldots,16\}$ be given by $R=\{(x,y):4y=5x-3,\,x,y\in M\}$. Then the minimum number of elements required to be added in $R$, in order to make the relation symmetric, is equal to
Let $A = \{1, 2, 3, \ldots, 10\}$ and $B = \left\{\frac{m}{n} : m, n \in A,\, m < n \text{ and } \gcd(m,n) = 1\right\}$. Then $n(B)$ is equal to:
Let $S = \mathbb{N} \cup \{0\}$. Define a relation $R$ from $S$ to $\mathbb{R}$ by $R = \left\{(x,y) : \log_e y = x \log_e\left(\frac{2}{5}\right),\, x \in S,\, y \in \mathbb{R}\right\}$. Then, the sum of all elements in the range of $R$ is equal to:
Let $R$ be a relation defined on the set $\{1,2,3,4\}\times\{1,2,3,4\}$ by $R=\{((a,b),(c,d)):2a+3b=3c+4d\}$. Then the number of elements in $R$ is
Let the relations $R_1$ and $R_2$ on the set $X=\{1,2,3,\ldots,20\}$ be given by $R_1=\{(x,y):2x-3y=2\}$ and $R_2=\{(x,y):-5x+4y=0\}$. If $M$ and $N$ be the minimum number of elements required to be added in $R_1$ and $R_2$, respectively, in order to make the relations symmetric, then $M+N$ equals
Let $A=\{1,2,3,4,5\}$. Let $R$ be a relation on $A$ defined by $x\,R\,y$ if and only if $4x\leq5y$. Let $\mathrm{m}$ be the number of elements in $R$ and $\mathrm{n}$ be the minimum number of elements from $A\times A$ that are required to be added to $R$ to make it a symmetric relation. Then $\mathrm{m}+\mathrm{n}$ is equal to: