## Evaluate a fair game [closed]

I'm not a mathematician, so my question may be not so clear, sorry.

Let's say we toss up an ideal coin and win 1 dollar on heads and lose 1 dollar on tails. So, expected value is M = 1×0.5 − 1×0.5 = 0. It may be interpreted as: we will gain/lose nothing playing a game for a long time. It is pretty clear.

Now, let's consider bankroll size. It will be changed on every coin flip. For Heads Tails Tails Tails Heads sequence, bankroll size will be 1, 0, -1, -2, -1 dollar. As I understand, bankroll size is a random variable. Is it even possible to evaluate this random variable somehow? How to calculate expected value and variance? May I evaluate minimum and maximum of bankroll size?

Thanks

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This is not really the right forum for such a question. This is a site intended for questions of interest to professional mathematicians. The FAQ has some more appropriate websites for such questions. – Lavender Honey Nov 14 2009 at 0:42
FC et al - remember you can flag questions for moderator attention. We'll close questions more promptly when this happens. Also, once you hit 3000 you can vote to close yourself! – Scott Morrison Nov 14 2009 at 4:59
@stas, closed, per explantion by FC above. More generally, if you feel the need to preface with "I'm not a mathematician" then you ought to have a particular reason in mind to expect that your question is "of interest to mathematicians". – Scott Morrison Nov 14 2009 at 5:02