Maths probability question

[Bing o]

So it's World Cup sweepstake time, and I have received an email telling us that the odds are 16-1 on winning.

There are four prizes and 32 teams, £5 a team.

Winner £80
Runner Up £40
3rd Place £25
4th Place £15

How are the odds 16-1???

[WorAl]

I think I understand your question, but not 100%.

I'm guessing it has something to do with the fact that half the teams get through to the knock out stages.

However, could it just be a made up figure, you know, like how they make odds up for horse racing, one horse will be 7-3 and another could be 150-1? But obviously being a sweep stake you won't have a favourite to pick as it's random selection, so making the odds even for all teams?

[ClareC]

Bet £5, £80 if you win is a 16-1 return (cos 80/5=16).

If it was a bookies you'd also get your £5 stake back on that too though.....

Also there's prizes for second thrid etc.... so the bet your making doesn't really equate on that way......

[Size Nine Elm]

Here we go, probability again...

32 teams, £5/team. Your probabilistic expected return is £5... (zero sum game).

But there are only 4 'winning' teams out of 32, so its actually 7-1 odds (or 1/8 probability).

[Get Karter]

You are mixing 'Probability' (in the title of your thread) with 'Odds'.

The probability of picking the winning team in your sweepstake is 32:1

The odds offered are 16:1

[pugwash4x4]

Your return is 16:1 (those are the odds), but the chances (probability) of winning may or may not be 32:1- its dependant on whether all 32 teams have the same chance of winning or not.

my suggestion would be that you really have a 5:1 or maybe 6:1 chance of winning if you can make a good judgement on who is likely to win.

in these circumstances it may be prudent to pay out £30 on the 6 likeliest teamts to win- int he knowledge that you will probably clear up the top prize, and if not you will at least in 2 or 3 of the next few prizes- and probably still make a profit.

[Get Karter]

pugwash4x4 said:

my suggestion would be that you really have a 5:1 or maybe 6:1 chance of winning if you can make a good judgement on who is likely to win.

It's a sweepstake, so you don't get to choose who you are picking.
Hence the 32:1 chance of picking the winner.

[MikeO996]

You have a 1 in 32 chance of winning, and if you win you get 16 times your stake - doesn't sound great - the only way you'd get at 32-1 payout is if there was only the one prize.

When you look at gambling the maths never stack up in your favour - even when there is no profit involved.

[Bing o]

Ah, having reread the email, he does say odds, so I guess that's right.

Damn!!

[elster]

The probability is 0.125.

This doesn't answer anything, so I guess the odds are made up.