Let $R$ be a relation in the set of natural numbers $N$ defined by $R = \{(a, b) : a = b - 2, b > 6\}$. Which of the following is correct?

$R$ is a relation on $\mathbb{N}$ given by $R=\{(x, y): 4x+3y=20\}$. Which of the following belongs to $R$?

Let the number of elements of the sets $A$ and $B$ be $p$ and $q$, respectively. Then, the number of relations from the set $A$ to the set $B$ is

Let $A = \{1, 2, 3, 4, \ldots, 10\}$ and $B = \{0, 1, 2, 3, 4\}$. The number of elements in the relation $R = \{(a, b) \in A \times A : 2(a - b)^2 + 3(a - b) \in B\}$ is $.........$.

Let $A = \{1, 2, 3, \ldots, 10\}$ and $R$ be a relation on $A$ such that $R = \{(a, b) : a = 2b + 1\}$. Let $(a_1, a_2), (a_2, a_3), (a_3, a_4), \ldots, (a_k, a_{k+1})$ be a sequence of $k$ elements of $R$ such that the second entry of an ordered pair is equal to the first entry of the next ordered pair. Then the largest integer $k$,for which such a sequence exists,is equal to:

If $n(A) = 2$ and the number of relations from set $A$ to set $B$ is $1024$, then $n(B)$ is