5. Suppose that the proposer in the ultimatum game may not propose fractional amounts, and therefore must propose $0, $1, $2. ...,, or $10 (see figure below). As always, the responder must Accept (A) or Reject (R). SO $1 $2 $a ($6.54) ISO. SO (a) Suppose, first, that this game is played by two egoists, for whom u(x, y)=x. Find all subgame-perfect equilibria in this game. (10 points) (b) Suppose, second, that this game is played by two altruists, for whom u(x,y)=2/3\\x+1/3vy. Find all subgame-perfect equilibria in this game. (10 points)