Question

If $A=\{a,b,c\},B=\{1,2\}$, then find the number of possible one-one functions from $A$ to $B$.

Answer 1

One-one functions are possible from $A$ to $B$ when

$n\left(A\right)\le n\left(B\right)$

Here, $n\left(A\right)=3,n\left(B\right)=2$

Here $n\left(A\right)>n\left(B\right)$

Number of possible one-one functions from $A$ to $B=0$.

$\therefore$Number of possible one-one functions from $A$ to $B$ is $0$