Given, $A = \{ 2,3,4\} ,B = \{ 2,5,6,7\}$.

Construct an example of each of the following
(i) an injective mapping from $A$ to $B$.
(ii) a mapping from $A$ to $B$ which is not injective.
(iii) a mapping from $B$ to $A$.

It is given that,, $A = \{ 2,3,4\} ,B = \{ 2,5,6,7\}$

(i) Let $f:A \to B$ denote a mapping

$f = \{ (x,y):y = x + 3\}$

i.e. $f = \{ (2,5),(3, - 6),(4,7)\}$, which is an injective mapping.

(ii) Let $g:A \to B$ denote a mapping such that

$g = \{ (2,2),(3,5),(4,5)\}$, which is not an injective mapping.

(iii) Let $h:B \to A$ denote a mapping such that

$h = \{ (2,2),(5,3),(6,4),(7,4)\}$, which is a mapping from $B$ to $A$.