This is combination
number of ways of choosing 3 players from 7 players
[tex]=^nC_r^{}[/tex]n = 7 and r = 3
[tex]=^nC_r\text{ = }\frac{n!}{(n-r)!r!}[/tex][tex]\begin{gathered} =\text{ }\frac{7!}{(7-3)!3!} \\ =\text{ }\frac{7!}{4!3!} \end{gathered}[/tex][tex]\begin{gathered} =\text{ }\frac{7X6X5X4X3X2X1}{4X3X2X1X3X2X1} \\ =\text{ }\frac{5040}{144} \end{gathered}[/tex]= 35 ways