We have the following given p1 - probability for outcome 1 p2 - probability for outcome 2 p3 - probability for outcome 3 v1 - amount of money that you will win or lose for outcome 1 v2 - amount of money that you will win or lose for outcome 2 v3 - amount of money that you will win or lose for outcome 3
Therefore, p1v1 + p2v2 + p3v3 is the average money you win or lose in playing the game.