Answer:
720
Step-by-step explanation:
Since we are choosing a subset of 3 people from a set of 10 people, and arranging the 3 people according to relative strength, the answer can be obtained by computing P(10,3).
Â
 P(10,3)=10! / (10-3)!
= 10!/7!
Rewrite  10 !  as Â
10 * 9 Â * 8 Â * 7 ! Â / 7!
Cancel the common factor of  7 !  and divide ( 10  * 9 * 8 ) by  1
10 Â * 9 Â * 8 = 720