Answer: 504
Step-by-step explanation:
When we select r things from n things in a order , we use permutations.
Formula for permutation: [tex]^nP_r=\dfrac{n!}{(n-r)!}[/tex]
Given : The number of family members who are potential kidney donors. = 9
Number of people needed to be selected for best match, a second-best match, and a third-best match ( in an order)=3
Then, the number of possible orders are = [tex]^9P_3=\dfrac{9!}{(9-3)!}[/tex]
[tex]=\dfrac{9\times8\times7\times6!}{6!}=504[/tex]
Hence, the number of possible orders 504.
