Question

Let $n(A)=4$ and $n(B)=6$. Then, the number of one-one functions from $A$ to $B$ is

• A. 24
• B. 60
• C. 120
• D. 360

Answer 1

Answer: (D)

Given, $n(A)=4$ and $n(B)=6$
Here, $n(B)>n(A)$
Then, the number of one-one functions
$={}^6{P}_4=\frac{6!}{2!}=360$