Answer:
Total number of people = 13
A:
Number of ways to choose 10 players to take the field = 13C10
=

= 286
B:
This is given as: 13P10
=
=

= 1037836800
C:
This is given as:
(3C1 x 10C9) + (3C2 x 10C8) + (3C3 x 10C7)
Solving this we get the answer as = 285