Riddles and Brainteasers

That is why I only play poker. My EV (expected value), at the low limits I play, based on the difference between my ability to calculate odds/play is more than enough to offset the rake. It doesn't take many poor players at the table to make that true.

That is why I did not mention poker :D
 
Monty Hall always gives his contestants a choice of three prizes that are unknown, and each concealed behind a seperate door. One is a grand prize, and the other two are booby prizes, and the contestant knows this. After they pick the prize behind door number 1, 2, or 3, he shows them the booby prize behind one of the two doors they did not pick. Then he gives them the option to choose to keep their original selection, or to pick the last remaining door. If you are the contestant, what should you do? Does it matter? What are the chances the prize is behind the door you first picked, and what are the chances the prize is behind the remaining door you didn’t pick?
Switch, see mythbusters for test data.
 
Actually, no. Never switch. You are discounting the (many) gambler's belief that "odds" do not matter, that there are other factors at play - luck, intuition, whatever. If gamblers believed in odds there would be no-one playing in casinos as there are no games there where the odds are not in the house's favor to some degree (excluding formerly? barred activites like blackjack card counters).
I understand what you're saying, but the math for this problem says otherwise. You are far more likely to get the prize if you switch doors. This has been proven over and over again (and even Mythbusters did it). :)
 
I understand what you're saying, but the math for this problem says otherwise. You are far more likely to get the prize if you switch doors. This has been proven over and over again (and even Mythbusters did it). :)

Not if you picked right the first time. Then your odds of getting the prize drop to zero if you switch. The gambler (or anyone else for that matter) might well think he picked right the first time and it is not about math.

What if you were betting your life? What if you made the initial choice under the threat of death and based your selection on whatever intuition, gut feeling, prayer, or god's blessing you think you had coming. Would you be so quick to change based on "probability". It ain't always about math. The question is not which option has a statistically higher chance of success, it is about what you would do in your ONE chance, not some hypothetical sufficiently large sample of events. People are not wrong for sticking with their original instinct

Sorry to get all deep and sh*t. :D
 
Not if you picked right the first time. Then your odds of getting the prize drop to zero if you switch. The gambler (or anyone else for that matter) might well think he picked right the first time and it is not about math.

What if you were betting your life? What if you made the initial choice under the threat of death and based your selection on whatever intuition, gut feeling, prayer, or god's blessing you think you had coming. Would you be so quick to change based on "probability". It ain't always about math. The question is not which option has a statistically higher chance of success, it is about what you would do in your ONE chance, not some hypothetical sufficiently large sample of events. People are not wrong for sticking with their original instinct

Sorry to get all deep and sh*t. :D


And that is why people don't switch, also explored in the mythbusters segment, thing is you never had any clue what door hid what. It ain't a game of skill but chance.
 
Not really. I also used to hang with some heavy gamblers and I know that they factor luck, intuition, and other intangibles in. As do I. Like I said, plenty of serious gamblers go to Vegas and play blackjack where the most skillful (non-counting) play still has a house advantage.

I didn't say bad gamblers don't do that lol, that's how those casinos exist.:rofl::rofl:
I'm talking about the pros who make a living at it. Remember, 80/20 rule applies to everything. I'm just saying don't rule out people using odds, they are the ones that win. MIT got busted out of all casinos for life over their ability to factor odds instantly in their heads.:rofl::rofl::rofl:
 
Not if you picked right the first time. Then your odds of getting the prize drop to zero if you switch. The gambler (or anyone else for that matter) might well think he picked right the first time and it is not about math.

What if you were betting your life? What if you made the initial choice under the threat of death and based your selection on whatever intuition, gut feeling, prayer, or god's blessing you think you had coming. Would you be so quick to change based on "probability". It ain't always about math. The question is not which option has a statistically higher chance of success, it is about what you would do in your ONE chance, not some hypothetical sufficiently large sample of events. People are not wrong for sticking with their original instinct

Sorry to get all deep and sh*t. :D

Factoring in luck, lol, you made my day. Believing you have skill at picking a door. Really?

The Monty Hall Problem is strictly mechanical, switch you win 2/3's of the time, don't you lose 2/3's of the time. Your cognitive and behavioral biases will never help you here. Never ever.
 
Not really. I also used to hang with some heavy gamblers and I know that they factor luck, intuition, and other intangibles in. As do I. Like I said, plenty of serious gamblers go to Vegas and play blackjack where the most skillful (non-counting) play still has a house advantage.

If you play when the house has an advantage then your lifetime (win)lose will be a function of monies risked and time spent playing. It is easily modeled and the best way to lock in a lose equal to the house advantage is frequent play. The error around that is why individuals think they are having a good run (or bad) yet the house (having many more samples) consistently yields a constant rate. The ability to confuse stochastic error with skill is what keeps casinos operating.
 
Factoring in luck, lol, you made my day. Believing you have skill at picking a door. Really?

The Monty Hall Problem is strictly mechanical, switch you win 2/3's of the time, don't you lose 2/3's of the time. Your cognitive and behavioral biases will never help you here. Never ever.

Meh, you believe what you want to believe and I will believe what I want to believe. Math and science describe only a small portion of human experience. They are a subset that some think is a superset.
 
Meh, you believe what you want to believe and I will believe what I want to believe. Math and science describe only a small portion of human experience. They are a subset that some think is a superset.

I don't think math nor science is in anyway complete, but I'll wager if you run the experiment in any unbiased way you'll find that people who choose not to switch will win 1/3 of the time. You will also find that this occurs regardless of their reason (luck, inspiration, faith, or conviction) for not switching.

If you find differently, and there is not an error, it will be one of the greatest finding in human history. A finding, btw, that has been sought by many in many different ways without success.
 
I don't think math nor science is in anyway complete, but I'll wager if you run the experiment in any unbiased way you'll find that people who choose not to switch will win 1/3 of the time. You will also find that this occurs regardless of their reason (luck, inspiration, faith, or conviction) for not switching.

If you find differently, and there is not an error, it will be one of the greatest finding in human history. A finding, btw, that has been sought by many in many different ways without success.

I am not talking about a study or a survey or an experiment. I am talking about one occurrence. See my prior post re betting your life. Personally, I do not run by life by statistics. I would rather run it by magic or inspiration or what have you. Like I said, you believe what you like and I will believe what I like.

You may or may not enjoy this lecture.

Live by the foma that make you brave and kind and healthy and happy.
-Book of Bokonon 1:5
 
I am not talking about a study or a survey or an experiment. I am talking about one occurrence. See my prior post re betting your life. Personally, I do not run by life by statistics. I would rather run it by magic or inspiration or what have you. Like I said, you believe what you like and I will believe what I like.

You may or may not enjoy this lecture.

Live by the foma that make you brave and kind and healthy and happy.
-Book of Bokonon 1:5

Feel free to let them know if they don't pick the winning door you will shoot them, then count the bodies.

Anyway, your position is spiritual and untestable - the very epitome of a belief - and I encourage all to believe what they will...
 
Feel free to let them know if they don't pick the winning door you will shoot them, then count the bodies.

Anyway, your position is spiritual and untestable - the very epitome of a belief - and I encourage all to believe what they will...

Again, you insist on a statistical sampling when the question is what would you do in your one occurrence, "If you are the contestant, what should you do?" :wink2:
 
Again, you insist on a statistical sampling when the question is what would you do in your one occurrence, "If you are the contestant, what should you do?" :wink2:

The question is as simple as "do you prefer a 1/3 chance or a 2/3 chance" - so you are the contestant, what should you do?
 
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Two sharpshooters are to compete in a contest on who is the quicker shot. It is a single shot rifle, and assume that their firing speed is constant regardless of how many shots they fire.

Timing begins with the first shot.

Person A fires 5 shots in 5 seconds.
Person B fires 10 shots in 10 seconds.

Who is the quicker shot?
 
Again, you insist on a statistical sampling when the question is what would you do in your one occurrence, "If you are the contestant, what should you do?" :wink2:

I use my skill and intuition to fully understand the question being asked of me, pick a door, then switch.
 
Two sharpshooters are to compete in a contest on who is the quicker shot. It is a single shot rifle, and assume that their firing speed is constant regardless of how many shots they fire.

Timing begins with the first shot.

Person A fires 5 shots in 5 seconds.
Person B fires 10 shots in 10 seconds.

Who is the quicker shot?

A shoots 4 shots over a period of 5 seconds (starts with first shot) for a rate of 1.25 seconds per shot

B shoots 9 shots over a period of 10 seconds for a rate of 1.11 seconds per shot

So, B is faster
 
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Gun is already loaded at first shot so shooter a fires 5 shots and reloads 4 times, shooter b fires 10 shots and reloads 9 times. 9/10 > 4/5
 
I should have added, "prove your answer"
Too Late!

clock starts @ first shot (I saw this on the discovery channel- so it must be correct :) ).
A: 4 shots/5 sec = 0.8 shots/sec
B: 9 shots/10 seconds = 0.9 shots/sec

0.9> 0.8
 
Too Late!

clock starts @ first shot (I saw this on the discovery channel- so it must be correct :) ).
A: 4 shots/5 sec = 0.8 shots/sec
B: 9 shots/10 seconds = 0.9 shots/sec

0.9> 0.8
Speaking of late
 
Too Late!

clock starts @ first shot (I saw this on the discovery channel- so it must be correct :) ).
A: 4 shots/5 sec = 0.8 shots/sec
B: 9 shots/10 seconds = 0.9 shots/sec

0.9> 0.8

There ya go...you get a:

Correct!
 
Meh, can't make everyone happy. I made the call at home plate and ya'll gonna have to live with it!

: )
 
Two motorcycles are on a single lane road 25 miles apart, facing each other. At the sound of a starting gun they ride towards each other, one at 20 mph, the other at 30 mph.

The instant the gun sounds a fly is startled off the helmet of the slower rider and heads toward the faster at 40 mph. The instant he reaches the faster rider he reverses course, heading towards the slower rider. This ping ponging continues until all 3 eventually collide.

How far does the fly travel?
 
Two motorcycles are on a single lane road 25 miles apart, facing each other. At the sound of a starting gun they ride towards each other, one at 20 mph, the other at 30 mph.

The instant the gun sounds a fly is startled off the helmet of the slower rider and heads toward the faster at 40 mph. The instant he reaches the faster rider he reverses course, heading towards the slower rider. This ping ponging continues until all 3 eventually collide.

How far does the fly travel?

20 miles
 
There are 100 taxi lights lined up in a row. Each bulb has its own switch. There are 100 pilots lined up in a nearby hanger. Each bulb and each pilot is number consecutively 1 to 100. The first pilot leaves the hanger and turns on every bulb. Once done, the second pilot leaves the hanger and throws every other switch (2, 4, 6, ..). Then the third pilots throws every third switch (3, 6, 9). This continues until all pilots have gone.

Is bulb 64 lit or dark at the end? How about bulb 83? Why.
 
Fly riddle solution

The simple answer is not to worry about the "ping ponging" the fly does.
The motorcycles have a closing rate of 50mph, so they will cover the 25 miles in half an hour. (The slower one will have traveled 10 miles, the faster one, 15.) In half an hour at 40mph, the fly will cover 20 miles.
 
Fly riddle solution

The simple answer is not to worry about the "ping ponging" the fly does.
The motorcycles have a closing rate of 50mph, so they will cover the 25 miles in half an hour. (The slower one will have traveled 10 miles, the faster one, 15.) In half an hour at 40mph, the fly will cover 20 miles.

Thanks, that is the observation that lets you get past the distraction of integrating over an ever shrinking ping pong trip...
 
There are 100 taxi lights lined up in a row. Each bulb has its own switch. There are 100 pilots lined up in a nearby hanger. Each bulb and each pilot is number consecutively 1 to 100. The first pilot leaves the hanger and turns on every bulb. Once done, the second pilot leaves the hanger and throws every other switch (2, 4, 6, ..). Then the third pilots throws every third switch (3, 6, 9). This continues until all pilots have gone.

Is bulb 64 lit or dark at the end? How about bulb 83? Why.

64 is on
83 is off

I'll let everyone think a bit more before explaining why.
 
Good time to remind folks there are 10 types of people, those that understand binary and those that don't.
 
My preferred solution isn't binary, fwiw.
 
I didn't factor in a binary solution either. :rolleyes2:
 
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