Pure maths, physics, chemistry, etc.: brain-training tasks that have nothing to do with trade [Part 2] - page 3

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Reshetov:
There is nothing to expose. "Paradox" is based on the player's ability to choose between profitable and unprofitable play. If the player has that option, then there is no problem and no paradox.
Nice try. Score.
 
TheXpert:
As always under-read.

Likewise.

TheXpert:


The paradox is based on the alternation of two (or more) losing strategies.

But, one of the so-called "losing strategies" is assembled from two games, and with the right to choose between a losing game and a profitable one.
 

I almost don't see any pure mathematics... Let's pour oil on the fire [4 points on braingames.ru]:

Фокусник берет колоду из 52 карт, как в блэкджеке, и отдает ее зрителям. Зрители выбирают (каким угодно способом) любые 5 карт и отдают их помощнику фокусника. Тот смотрит на карты и называет фокуснику 4 из них. В ответ фокусник называет пятую. Кроме мастей и значений карт, фокусник не получает никакой дополнительной информации (помощник говорит ровным голосом, без пауз и т.д.). Каким образом фокуснику удается "угадать" пятую карту?

Please don't google and don't write solutions known in advance here.

From the comments:

  • 52 = 4*13, i.e. a deck without jokers.
  • No cheating, pure mathematics. All information the magician has is the cards named by the helper (value + suit), together with the order of the cards.

P.S. They write that the trick is sort of Akopian. They also say that the problem can also be solved for a deck of 124 different cards, but the solution is very complicated.

I've been thinking over the problem for a few days, I've gone through several variants, but each time I'm missing a trivial thing to solve it.

 
Mathemat:

I almost don't see any pure mathematics... Let's pour oil on the fire [4 points on braingames.ru]:

Please don't google and don't write solutions known in advance here.

From the comments:

  • 52 = 4*13, i.e. a deck with no jokers.
  • No cheating, pure mathematics. All information the magician has is the cards named by the assistant (value + suit), together with their order.

P.S. They write that the trick is sort of Akopian. They also say that the problem can be solved for a deck of 124 different cards, but the solution is very complicated.

I've been thinking over the problem for a few days, I've gone through several variants, but each time I'm missing a trivial thing to solve it.


No way ((

In the distant years of working as a concert administrator I got to know prestidigitation, there are no other options

Maybe the conditions are not complete ?

 

If the suits are strictly ordered in agreement with the assistant, the cards in the assistant's hand will also be strictly ordered.

One of the 48 (52-4) cards must be coded.

By rearranging the set of 4 cards in the strictly ordered order, you can code 4! (=24) cards.

Total: one bit is missing.

One bit can be communicated in a thousand ways.

Even if you limit it to card descriptions: by changing the order of one card description ("ten of hearts" / "ten of hearts") you can increase the set to encode by 32 times (2^5)

Something like this.

 

Makes sense, Vladimir. But:

"десятка червей" / "червонная десятка"

You can't do that. There's no distinction here (that's also from the comments): viewers will notice the cheating.

It's all very fair: any way of naming a card that communicates suit and value is equivalent to any other in the sense of the information being conveyed. A vector (meaning, suit) is being conveyed.

The conditions are complete, there are quite a few people on the site who have already solved it.

 

.......Так нельзя.

Here we go..........

;)

 
Then there is no way. The permutations only allow 24 values to be encoded.
 
... and the starting suit is to add the bit you are looking for.
 
More precisely, tara. There can only be one suit in a deck of 5 cards (flush, if from poker).
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