Question

If set $A$ has $3$ elements and set $B$ has $4$ elements, then number of injective functions that can be defined from $A$ to $B$ is

• A. $144$
• B. $12$
• C. $24$
• D. $64$

Answer 1

The correct option is C $24$

The total number of injective function's from set $A$ containing $3$ elements to set $B$ containing $4$ elements is equal to the total number of arrangements of $4$ by taking $3$ at a time $={}^4{P}_3=24.$