Naked Science Forum

General Science => General Science => Topic started by: don kennedy on 27/04/2010 02:30:02

Title: What's wrong with the maths here?
Post by: don kennedy on 27/04/2010 02:30:02
don kennedy asked the Naked Scientists:
   I get this email many times every day, i assume its not true, but is it?

"I quit my job. Now I`m making $8000-$15000 a month by "working" 4-5 hours a day :) I`ll tell you how I`m doing it because you also halped me 2 years ago when I needed help.

I found a way how to win in roulette everytime, I only bet on reds or on blacks. If you bet $1 on reds and it goes red you win $2, if it goes black you loose your $1.

So I bet $1 on reds, if it goes black I bet $3 on reds, if it goes black bet $8 on reds (I always multiple my previous lost bet around 2.5), if it AGAIN goes black bet $20 on reds, if this time it goes red I win $40.

So I bet $1   $3   $8   $20 = $32  and I win $40, so I just made $8 and it took me around 2 minutes. Did someone ever paid you $8 for 2 minutes work?  If I play for 4 hours I make $300-$500, EVERYTIME. That`s why I quit my daily job."

can i really quit my job?

thanks!

What do you think?
Title: What's wrong with the maths here?
Post by: wolfekeeper on 27/04/2010 02:39:43
It's a con. If they could really do that stuff then they wouldn't have to send scummy spam mail to try to make money.
Title: What's wrong with the maths here?
Post by: JP on 27/04/2010 04:02:57
You're not winning every time.  You only win the last time you play, and that only matters if you have enough money so that you never stop gambling.  The important point they ignore is that even if you've gone through three spins and lost, you're still 50% likely to win or lose on the last spin.  Your odds don't change just because you've already lost.  In the example above, you stand to make $8 total if that spin comes up a win, but if that spin comes up a loss, you stand to lose $32.  Even if you win this, you now only have $40.  If you had lost that spin, you would need to bet $98 on the next spin.  Eventually you'll lose this critical spin (since you have a 50% shot at it) and end up losing all your money.
Title: What's wrong with the maths here?
Post by: jrussell on 28/04/2010 16:33:15
as a former croupier, i can tell you the flaws in this system are two-fold -

1) generally speaking, there is a table limit. on a £500 limit, you have only 8 spins before being unable to bet double again.

2) the big decider is the 0 and or double 0 which damage your odds.