Question 1149764
Find the expected payback for a game in which you bet ​$10 on any number from 0 to 99. If your number comes​ up, you get ​$500.
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In this game, you will lose 99 out of 100 plays, and win 1 out of 100 plays.  Assuming the bet is always collected by the house:
(-10)*(99/100) + (500-10)*(1/100) = -5<br>

The expected payback for this game is to LOSE $5 per play (on average) for a large number of plays of this game.

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EDIT: The solution I gave assumes each number is equally likely to come up.