Find the expected payback for a game in which you bet 
2000.
Solution:-
Let x, the random variable, represent the possible amounts of payback, where payback is the amount won less the cost.
The payback for winning is 
20 = 1980.
The payback for losing is 
20 = 
1980
1980)-(0.0100 ) +(
0.00.
Therefore , the expected payback is $0.00.
Note that a game with an expected value of 0 is called a fair game.