Simple gambling problem

Simple gambling problem

Posers and Puzzles

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L

Joined
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04 Apr 08
4 edits

Originally posted by eldragonfly
My mistake, still stop being rude, it serves no purpose. 😉
OK, well you implied I was a "dummy", so I returned the favor.

Yes, I could see how their question is ambiguously offered. But hopefully you see now why they quote the answer they quote.

I think your alternative interpretation is a more interesting question, but that also becomes ambiguous. For instance, are we supposed to have knowledge of what particular face card is initially drawn and removed from the deck, or do we only know that it is a face card? The most interesting case would be where we only know that it was a face card (we don't know which particular face card or type of face card). In that case, I think mtthw and geepamoogle have already given the right answer on the previous page.

e
leperchaun messiah

thru a glass onion

Joined
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04 Apr 08

Originally posted by LemonJello
OK, well you implied I was a "dummy", so I returned the favor.

Yes, I could see how their question is ambiguously offered. But hopefully you see now why they quote the answer they quote.

I think your alternative interpretation is a more interesting question, but that also becomes ambiguous. For instance, are we supposed to have knowledge of what p ...[text shortened]... card is initially drawn and removed from the deck, or do we only know that it is a face card?
The problem was poorly worded.

L

Joined
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3061
04 Apr 08

Originally posted by eldragonfly
The problem was poorly worded.
Yes, I would agree with you on that.

e
leperchaun messiah

thru a glass onion

Joined
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16870
04 Apr 08

Originally posted by LemonJello
Yes, I would agree with you on that.
There you go.
But i was trying to work up to bayes theorem, in other words i don't really fathom the solution to the baseball playoff game, other than in my mind the first answer would something involve just *crunching* the games won stats.

P
Bananarama

False berry

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04 Apr 08

Originally posted by eldragonfly
There you go.
But i was trying to work up to bayes theorem, in other words i don't really fathom the solution to the baseball playoff game, other than in my mind the first answer would something involve just *crunching* the games won stats.
Try the problem on p.8 of this thread. Part 1 is easy. Part 2 will help you understand conditional probability.

a

Joined
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04 Apr 08
1 edit

Originally posted by PBE6
I ran a simulation too. Each number below represents 5000 trials, and the average is the value for all 50,000 trials:

0.556419113
0.557171952
0.541043724
0.563888088
0.543978749
0.576020851
0.567821491
0.565077508
0.582945285
0.568644561

Average = 0.562301132

This is closer to mtthw's answer (56.5% ) than my answer (56.8% ), which gives me added confidence in mtthw's answer.
did you take into consideration the score (11-4) ?
you could do that when you run your simulation and see that because the mets won with almoust triple points increases the odds for them to have palyed in NY to 1.66 to 1

that goes double for mtthw!

m

Joined
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35068
04 Apr 08

Originally posted by alexdino
did you take into consideration the score (11-4) ?
you could do that when you run your simulation and see that because the mets won with almoust triple points increases the odds for them to have palyed in NY to 1.66 to 1

that goes double for mtthw!
Good try 🙂

a

Joined
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04 Apr 08

Originally posted by PBE6
I can help with the concept, although I'll drag in the Monty Hall problem (the bazillionth time for some of these guys).

You're playing Let's Make a Deal with Monty Hall. There are three doors on stage, and behind one there is a prize (the prize door is randomly selected before the show, 1/3 chance it could be behind any door). For simplicity's sake, there ...[text shortened]... should have a good handle on what conditional probability means and how to use it.
you should swich
i assum the chances are 2 to 1

a

Joined
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04 Apr 08
1 edit

Originally posted by mtthw
Good try 🙂
did you try it?
what was your result?
and i say it maters because its given in the original text

m

Joined
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35068
04 Apr 08

Originally posted by alexdino
did you try it?
what was your result?
and i say it maters because its given in the original text
The original problem says nothing about score distributions, it only gives probabilities for win/loss.

It had crossed my mind that you could infer something from the actual scoreline, but we aren't given nearly enough information to do that.

g

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04 Apr 08
3 edits

The good old Monty Hall problem. The intuitive answer is that either door is equally likely to have the prize and therefore switching is an even trade of odds.

However, in the Monty Hall problem, the door being opened doesn't provide as much information as it would seem to, because the door selected is not random, but rather is intentionally a losing door. The host knows the layout of the doors, and he always has a losing door to choose, so he can do that.

Had the door that was selected been a random choice (meaning there was a chance that the revealed door held the prize), it WOULD be the case that switching would be equally likely to win or lose.

I heard a very simple way to reason this out that makes sense, but it's not coming to me now.

I think it went something like this.

When you first choose the door, you have 1-in-3 chance to be right. Since the revealed door will always be a losing door, that means the remaining door has a 2-in-3 chance of having the prize. Remember, the host always reveals a losing door, so if you chose wrongly, the remaining door will have the prize.

L

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04 Apr 08

Here's another problem about conditional probability to keep the thread going.

Suppose one is scheduled to play a best-of-five match where every game of the match is decisive: either a win or a loss results. The probability that he will win the first game is 1/2. But in subsequent games thereafter, the probability of his winning each game depends on the match history and his related confidence level:

If he won the previous game, he is feeling heightened confidence and the probability of his winning the upcoming game is 2/3. If he lost the previous game, he is feeling somewhat demoralized and the probability of his winning the upcoming game is only 1/3. There is an exeception to this rule, however. If he has won the last two games in a row, then he is really feeling on a roll, and his probability of winning the upcoming game is 3/4. If he has lost the last two games in a row, then he is really losing his confidence and his probability of winning the upcoming game is only 1/4.

What is the probability that he wins the match, given that he wins the first game of the match?

a

Joined
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05 Apr 08

Originally posted by LemonJello
Here's another problem about conditional probability to keep the thread going.

Suppose one is scheduled to play a best-of-five match where every game of the match is decisive: either a win or a loss results. The probability that he will win the first game is 1/2. But in subsequent games thereafter, the probability of his winning each game depends on ...[text shortened]... What is the probability that he wins the match, given that he wins the first game of the match?
please refrasethe question because it has too many lacunes

e
leperchaun messiah

thru a glass onion

Joined
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05 Apr 08

Originally posted by alexdino
you should swich
i assum the chances are 2 to 1
they go from a 1/3 to 1/2 but i still don't understand the mechanism for this.

e
leperchaun messiah

thru a glass onion

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05 Apr 08

Originally posted by mtthw
The original problem says nothing about score distributions, it only gives probabilities for win/loss.
that's what i thought.