Correct !

And here was I thinking "does Usain Bolt have a little brother?"

Here is one in the style I like.

Always invisible, yet never out of sight. What are they?

The letters "I" and "S". Too easy.

-Doug

Your eyes? They are invisible to you but others can see them. Unless they are closed. And you are not looking in a mirror. I'll get my coat

My kids' toys: they're always left scattered on the floor, yet I never see them so I'm always tripping over them!

Doug you are correct.
I apologize for my absence, I have been moving apartments and my car died

A King has 1,000 barrels of wine stored in his cellar. Unfortunately, the guards found an assassin that snuck in last night and poisoned exactly one of the barrels. Even one drop of poisoned wine would be enough to kill a man, but the poison takes 30 days before becoming fatal, plus or minus a few hours. The poison is colorless, odorless, and victims show no signs of being poisoned in the 30 days prior to dying.

In 31 days time, there will be a grand feast in which the King will need as much of the wine as possible. He has 10 prisoners on which to test the wine. His first idea is to give each prisoner a glass from 100 barrels of wine, and then when 1 prisoner dies, throw out all 100 barrels of which the dead prisoner drank from. However, his Jester speaks up and explains a solution that will pinpoint exactly which barrel is poisoned using the 10 prisoners.

What was the Jester's solution?

-Doug

Ahhh, nice puzzle. This is like the puzzle where you have only a certain number of weighings to find which object is either lighter or heavier. I can give a hint, but I'll hold off.

-d

My solution: If we had 4 barrels of wine, only one of which is poisoned, we could test them as follows using just two prisoners, Sam and Max, as follows:

Sam drinks from barrel A
Max drinks from barrel B
Sam and Max drink from barrel C.
Nobody drinks from barrel D.

After 30 days, if nobody dies the poison is in D. If only Sam dies, it is in A. If only Max dies is is in B. If both die, it is in C.

As this is essentially a binary code, then 10 prisoners can be used in this way to uniquely identify which of 2^10 barrels (= 1024) is poisoned.

Good job.

-Doug

I like that puzzle, though I would just force the assassin to say which barrel he poisoned, by forcing him to drink one drop from each of the other 999 barrels.

Find the opened barrel

Barrels of wine are stored on their side with a cork or other plug in the top. They are constantly being opened to check on the progress of the wine. It isn't possible to find which has been opened the night before unless the assassin spilled a bunch of wine that hasn't dried yet.

Similar, but a bit simpler because you are dealing with binary (live/die) rather than trinary (heavier, lighter, equal). The trick with the weighing is that most people treat it as binary and get a reasonable but sub-optimal answer (i.e. eight objects in three weighings when you can do it in two).

My solution was a bit more specific than Gus, but basically the same:
Each prisoner drinks from basically half of the barrels, but in overlapping regions corresponding to the binary bits positions. This allows for 1024 barrels as Gus pointed out, but works fine for fewer.
Numbering the barrels 0-999 and prisoners 0-9 makes decoding things easier if you know binary:

Prisoner (bit) #0: every other group of 1: (0, 2, 4, 6, 8, ..., 998)
Prisoner (bit) #1: every other group of 2: (0,1, 4,5, 6,7, ..., 998,999)
Prisoner (bit) #2: every other group of 4: (0-3, 8-11, 16-19, ..., 992-995)
Prisoner (bit) #3: every other group of 8: (0-7, 16-23, 32-39, ..., 976-983)
...
Prisoner (bit) #8: every other group of 128: (0-127, 512-639)
Prisoner (bit) #9: every other group of 512: (0-511)

They drink, and thirty days later we line them up 9-0 we have live = 1 and dead = 0:
Barrel 0: 0 0 0 0 0 0 0 0 0 0
Barrel 1: 0 0 0 0 0 0 0 0 0 1
Barrel 2: 0 0 0 0 0 0 0 0 1 0
Barrel 845: 1 10 1 0 0 1 1 0 1
Dave

I would love to see a more complex (e.g., hexadecimal, 16-state) version of this puzzle...

A man is sitting a at coffee enjoying his morning coffee and reading a newspaper. The front page of the paper talks about the trial and conviction in Flemington, as well as the death of Mr. Long. He flips the page to an article that states: "A recent study shows, that contrary to proper belief, the affects of the mustard gas in the first world war were longstanding." The man's bewildered. Why?

-Doug

I believe it might be that the noun form of affect means an emotion.

Callum

Nope!

-Doug

Something with the date? When was this Flemington Trial?

The man is bewildered because he can read the newspaper at all, while he is supposed to be blind, need glasses, or something similar?

Well, the Flemington trial was of Richard Hauptmann (Lindbergh kidnapping) in Jan-Feb 1935, and Mr. Long could be Huey Pierce Long, 40th Governor of Louisiana, who was assassinated in September 1935, so both these events could be in the paper at the same time.

Also, mustard gas is carcinogenic, so long term effects may have been well known in 1935. But, a mustard gas derivative, Mustargen, was the first anti-cancer drug, but it was not used as such until 1942.

So ... I think the solution may have nothing to do with these facts

Maybe he was bewildered because these stories happened at different times and should not have been in the same paper.

Or because the reported stories/facts contradicted each other in some way (many possibilities).

Or because he was Mr. Long and should not be reported dead.

Or because he had been exposed to mustard gas, but felt no longstanding effects.

Or because he is the scientist who carried out the mustard gas study, but his conclusions were not as reported.

Or because he was trying to find a connection or contradiction that wasn't there (like the rest of us in trying to solve this riddle).

Or because they charged him too much for his coffee.

Or because he saw the waitress levitating 6 inches off the ground. (now how's that for lateral thinking!)

Or because he had Alzheimer's, or was just a bit "cognitively challenged".

Or maybe the question "why?" doesn't even refer to the fact that the man is bewildered!

...

I could give *thousands* of possible answers to this riddle, so this is just guessing and not very interesting.

Often these riddles have some kind of "out-of-the-box" solution, but were written by someone who isn't very imaginative, so they don't appreciate just how many different solutions there could be. So then the riddle is more about understanding the mind of its creator.

However, assuming that the guy is bewildered by some contradiction between the stories, my best guess is that Mr. Long was in good health before he died, long after he was exposed to mustard gas. Is that correct?

Otherwise you'll need to give us some clues to narrow down the possibilities...

Because it should have said "effects"?

I'm guessing that was just a typo.

If he's reading about the Flemington trial, it's 1935. Before the start of WWII in 1939, what we now call the 'First World War' (as stated in the newspaper article), was known as the 'World War' or 'Great War'. He's bewildered because his newspaper seems to predict future world history.

A bit like discovering a Roman coin with a 100 BC date on it.

Ah yes, like The Flinstones celebrating Christmas.

My guess would be that he was in the trenches with mr Long, and he understands that if mr Long died, it is possible that he died from the long term effects of the mustard gas. Following that, he starts fearing for his own life (maybe they were both exposed to the gas?).

Ah yes! Or like finding a coin marked "Elizabeth I" which must be fake.

Correct!

-Doug

Or like seeing a T-1000 Terminator before it has been created. Oh, hang on a minute...

This one is easy and topical.

A Skewb is 14
A Puck is 12
A Starminx is 17
A Gigaminx is 19
A Kilominx is 21
A Cheese is 11
A Domino is 9

What number is a Pyraminx?

15

I also got 15 just by taking the average value of the numbers given (14.7), on the basis that the numbers seem to be normally distributed and so the mean should be the most likely.

No, not 15. No decimals or rounding involved.

More examples:

Qubami = 19
Pyramorphix = 30

Ah yes of course,
Pyraminx is 22.

Correct!

The number is the score using Scrabble tiles.

You get 2 cubes to make a calender, how do you put the digits on the cubes to make all the numbers from 01 to 31? You can only put one digit on each side of the cubes.

I like giving this one to students. "Walkthrough" below:
We get to pick two sets of six numbers. Clearly we need a one and a two on both cubes, to make 11 and 22. Less obviously, we need a zero on both, since if we only had one zero, we'd be able to make at most six single-digit dates (zero plus one number from the other cube). So 012*** and 012***. Let's just start filling things in according to what dates we can't write yet. 012345 and 012678 seems necessary to be able to write 01 through 08. With those cubes, we can write 01-08, 10-18, 20-28, 30 and 31 just by choosing the 0/1/2 that's not on the cube containing the other number we need. But wait! There's no 9! That's okay, use a font where an upside down 6 looks like a 9 and you're golden. 09, 19, and 29 are now possible as well, and we're done.

Here's one way to do it:

0,1,2,3,4,5 and 0,1,2,6,7,8

Note that 9 = 6 inverted, and you can shuffle the 3, 4, 5, 6/9, 7 and 8 between cubes, as long as both cubes have the numbers 0, 1 and 2.

Correct !

I see that Iranon got there first, so will let him set the next riddle...

I woke up this morning, I was still in my bed and without opening my eyes I knew it was freezing outside, how did I know?

I'd say either you had watched the weather the night before or your power had gone out and it was now freezing inside as well. There is also the odd possibility that your bed is outside.

Carl

All wrong !

Ok... maybe you could hear your neighbor shoveling snow off his driveway or scraping ice off his windshield.

Carl

Yes correct, I heard someone scratching!

I was going to say because you had left your bedroom window open and could feel an icy draft on your face - or maybe your eyes had frozen shut which is why you didn't (couldn't) open them.

A person wearing a red jacket walks around the corner a building on a cold overcast otherwise nondescript day. There is traffic to his left and he suddenly notices he's even with the shadow of the building. As he takes his next few steps he notices the shadow of the building is keeping pace with him before it accelerates out in front of him and disappears.

What is going on?

Bonus points if you can answer the following:
(1) Where is he?
(2) What day is it?
(3) Who is he?

Enjoy,
Carl

What is going on? Exactly as you described.

(1) Where is he? Walking around the corner of a building
(2) What day is it? A cold overcast otherwise nondescript day
(3) Who is he? A person wearing a red jacket

Reminds me of an English comprehension test.