Please help me to calculate the core of this easy coalitional game. I really didn't get it from my game theory course but want to understand the mechanism of calculating, describe it in detail please! Thank you!
The task is:
*Three players together can obtain $1$ to share, any two players can obtain $0.8$, and one player by herself can obtain zero.
*Then, $N=3$ and $v(1)=v(2)=v(3)=0$, $v(1,2)=v(2,3)=v(3,1)=0.8$, $v(1,2,3)=1$. Which allocation is in the core of this coalitional game?
b) $(0.4, 0.4, 0)$;
c) $(1/3, 1/3, 1/3)$;
d) The core is empty;