The theory of happiness. The curse of the director and the damned printers

The theory of happiness. The curse of the director and the damned printers I continue to acquaint the readers of Khabra with the chapters from my book The Theory of Happiness with the subtitle "Mathematical Foundations of the Laws of Meanness". This is not yet published popular science book, very informally telling about how mathematics allows a new degree of awareness to look at the world and people's lives. It is for those who are interested in science and for those who are interested in life. And since our life is complex and, by and large, unpredictable, the emphasis in the book is mainly on the theory of probability and mathematical statistics. Here theorems are ...
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What is the importance of ??? = ??? + 1? How to explain it on the fingers?

The author of the answer to Quora is Michael Griffin, postdoc on mathematics
 
 
What is the importance of ??? = ??? + 1? How to explain it on the fingers? Senia Scheidwasser gave very good, simple answer to this question, I recommend reading this brief version. But there is a much more surprising story of the Monstrous Moonshine hypothesis mixed with McKay's equation: from Jack Daniel's whiskey to black holes and quantum gravity.
 
 
In this story, symmetries and mathematical "groups" are often mentioned, so let's start with what is meant by the group in mathematics. A group can be represented as a way to reorder a set of objects, preserving a certain structure. The operations ...
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The Boschernitsyn theorem

In this paper we give a simple proof that the mapping of a compact metric space into itself that does not reduce distance is an isometry.
 
 
 
Display
The Boschernitsyn theorem
metric space with the metric of

are called isometries if for any

the equality
is valid.
. We shall prove the following assertion here:
 
 
Theorem. If

mapping of a compact metric space into itself, such that
 
 

 
 
for ...
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Friday PHP-quiz: a little adventure of the programmer Brad, one strange sequence and

Friday PHP-quiz: a little adventure of the programmer Brad, one strange sequence andprizes.Hello! We promised to do: we continue the series of mini-quizzes devoted to different programming languages ​​in our blog (previous: 1 (for knowledge of Python, PHP, Golang and DevOps) , .2 (completely Go) ). Today's issue is dedicated to PHP.  Under the cut - eight questions, a few adventures of the programmer Brad, one strange sequence and a cool meas as prizes. Quiz runs until 4 July.      The rules of the game   To the first , who will answer them correctly, we will send a set of Avito souvenir: a t-shirt with a php-elephant, socks and holivar bones (you can tell which backend ...
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Issue # 25: IT training - topical issues and tasks from leading companies

Today we have prepared the last issue of IT training in the current format.
 
Issue # 25: IT training - topical issues and tasks from leading companies
 
We picked up tasks for you from Cisco interviews. They ask questions not only about routing and hardware (there are such questions in the selection), but also logical tasks. The most interesting of them are waiting for you under the cat.
 
 
It should also be noted that this issue will be the last in this format, but will continue in a modified form. We decided to change the format and the site for the subsequent editions of IT training - the sequel will be in the Typical programmer.
 
...
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We calculate the probabilities for the article "Dishonest game, or how the organizers of the drawings deceive us"

We calculate the probabilities for the article "Dishonest game, or how the organizers of the drawings deceive us" Article with the analysis of the game of the well-known trading network has caused us in Cloud4Y lively interest. Here are a few excerpts to introduce you to the course:
 
One day, on a sunny spring morning, reading the city forum, I came across a link with a simple game from a well-known trading network. The game (action), dedicated to the World Cup, was an unpretentious field three to three, filled with soccer balls. Clicking on the ball, we opened the picture with this or that product. When opening three identical pictures, the participant was guaranteed a free receipt of the goods ...
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Issue # 24: IT training - current issues and tasks from leading companies

The new edition of IT training included tasks from the "blue giant", IBM.
 
 
Issue # 24: IT training - current issues and tasks from leading companies
 
 
In this company, with a rich historical past, also set logical tasks for interviews. Some of them, the most interesting in our opinion, we included in the selection. Under the cat you are waiting for tasks for applicants, as usual - not only simple, but also requiring reflection.
 
 

Questions


 
 
Chickens
 
A farmer sold a few chickens to four different customers on a particular day. It was such that each customer purchased half of the remaining chickens and a half chicken more.
 
 
Can you find out how many chicken ...[/h]
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Issue # 22: IT training - current issues and tasks from leading companies

We have prepared for you a new edition, which has already become a traditional, IT-training - a selection of tasks with interviews in an IT company in the world.
 
Issue # 22: IT training - current issues and tasks from leading companies
 
In the selected tasks got the task with the interviews Samsung. The competitor may also be asked about the code and Sherlock Holmes (no, not
dancing people), as one might think. We tried to vary the level of complexity - from simple to serious.
 
 

Questions


 
 
Faulty machine
 
We have 10 machines that produce screws, each weighing 1 gram. One of the machines, however, produces screws weighing 0.9 grams only. We are allowed only one ...[/h]
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Magnasanti is the biggest and most terrible city of SimCity

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