In a public good game, there are 4 players. Each player has $10, which s/he can keep or donate to a public pool. For any amount donated to the pool, a social planner will triple the amount and distribute it evenly to each player. What is the Nash Equilibrium donation and outcome? What is the socially optimal donation and outcome?

Hint: Pn = (10-Xn) + 0.75* (x1 + x2 + x3 + x4)