Posted by Hayli on Wednesday, September 29, 2010 at 8:44pm.
The game of roulette uses a wheel containing 38 pockets. Thirtysix pockets are numbered 1,2.....,36, and the remaining two are marked 0 and 00. The wheel is spun, and a pocket is identified as the "winner." Assume that the observance of any one pocket is just as likely as any other.
Suppose you bet $5 on a single numbersay, the number 18. The payoff on this type of bet is usually 35 to 1. What is your expected gain?

statistics  Reiny, Wednesday, September 29, 2010 at 9:30pm
prob of your number coming up is 1/36
expected gain = 35(5)(1/36) = 4.86
So, just like in every gambling game, in the longrun you would lose. 
statistics  Hayli, Wednesday, September 29, 2010 at 9:46pm
thank you

Correction  statistics  Reiny, Wednesday, September 29, 2010 at 11:01pm
the Prob of your number coming up is 1/38 , not 1/36
which changes the result to
5(35)(1/38) = 4.61
even worse than before