Examples of solving computer science problems
(basic course)
Information.
Theory:
1 GB \u003d 1024 MB
1 Mb \u003d 1024 Kb
1 Kb \u003d 1024 bytes
1 byte \u003d 8 bits
Convert 2 MB to KB, bytes, bits.2 Mb * 1024 Kb \u003d 2048 Kb
2 MB * 1024 KB * 1024 bytes \u003d 2097152 bytes
2 MB * 1024 KB * 1024 bytes * 8 bits \u003d bit
2 Mb * 1024 Kb \u003d 2048 Kb
2048 Kb * 1024 bytes \u003d 2097152 bytes
2097152 bytes * 8 bits \u003d bits
Convert a bit to MB, KB, bytesbit: 8 bits \u003d 3407872 bytes
bit: 8 bit: 1024 bytes \u003d 3328 KB
bit: 8 bit: 1024 bytes: 1024 KB \u003d 3.25 MB
bit: 8 bits \u003d 3407872 bytes
3407872 bytes: 1024 bytes \u003d 3328 KB
3328 Kb: 1024 Kb \u003d 3.25 Mb
Theory:
By default (unless specified specifically in the task), when solving the problem, a 256-character alphabet is indicated - the ASCII table (alphabet power \u003d 256 characters). This means that one character (letter, number, character, punctuation mark, space) accounts for 8 bits of information or 1 byte.
Determine the amount of information contained on a printed sheet of paper (duplex printing) if 40 lines of 67 characters per line fit on one side.Define the number of characters on one side of the sheet:
40 lines * 67 characters \u003d 2680 characters
Define the number of characters on 2 sides of the sheet:
2680 characters * 2 \u003d 5360 characters
Amount of information \u003d 5360 characters * 1 byte \u003d 5360 bytes
We translate in Kb: 5360 bytes: 1024 bytes \u003d 5.23 Kb
If it were necessary to get an answer in bit, then
Amount of information \u003d 5360 characters * 8 bits \u003d 42880 bits
We translate into 42880 bits in bytes: 8 bits \u003d 5360 bytes
We translate in KB 5360 bytes: 1024 bytes \u003d 5.23 KB
Theory:
where i is the amount of information in bits, N is the number of characters, the number of events
The symbol is a punctuation mark, a number, and special characters. And a space!
How much information will be contained on the page of the printed text when using the 32-character alphabet (60 lines of 56 characters per page).Number of characters per page \u003d 60 lines * 56 characters \u003d 3360 characters
By condition, a 32-character alphabet is used (i.e., the power of the alphabet \u003d 32 characters).
Then left "\u003e
The units of information for the right and left parts must be the same.
How many characters are contained on the page of the encyclopedic dictionary, if in the computer memory this page occupies 13 Kb?112 "height \u003d" 52 "bgcolor \u003d" white "style \u003d" vertical-align: top; background: white "\u003e 13 Kb * 1024 bytes * 8 bits \u003d 106496 bits
 |
The total number of characters on the page (for the previous task) \u003d 13312 characters
Total number of characters 13312 characters
Number of lines \u003d ------ \u003d ------
Number of characters per line 85 characters
»157 lines
How many bits are in the word INFORMATION?Since the default number of bits of information per 1 character \u003d 8 bits
(256-character alphabet, Russian language "href \u003d" / text / category / russkij_yazik / "rel \u003d" bookmark "\u003e Russian language 33 letters, in Latin - 26 letters.
Russian language:, i \u003d 6 bits (i should not be less than 6, because, and we have 33 letters
Latin:, i \u003d 5 bits.
The number of bits of information of one symbol of the Russian language is 1 more than in the Latin language.
Theory:
When formatting a floppy disk 3.5 (A), its physical size is 1.44 MB. However, only 1.37 MB is available for recording directly the user information itself, since 71.7 KB is allocated to create a disk directory and track zero.
How many 1.37 MB floppies are needed to save information from a 40 GB hard drive? And how muchCDs?40 GB * 1024 MB \u003d 40960 MB
The number of floppy disks \u003d 40960 Mb: 1.37 Mb \u003d diskettes.
That is, approximately 30 thousand floppy disks 3.5 (A)!
One CD-ROM contains approximately 700 Mb of information, then 40960 Mb / 700Mb \u003d 58.51? That is, approximately 59 CD-R discs of 700 MB each.
How many questions do you need to ask in order to guess the mysterious student from your class?
Suppose you have 27 people in your class.
Where N \u003d 27, i.e.
There is no exact degree for this equation (s).
In the first case, we will guess only out of 16 people, in the second of 32.
So, to guess from 27 people you need to get 5 bits of information,
i.e. ask 5 questions.
The number of characters on one page is 15 lines * 20 characters \u003d 300 characters
Total characters in the book n \u003d 300 characters * 20 pages \u003d 6000 characters
Total amount of information I \u003d bits in 1 character * n characters
5.86 Kb \u003d 48005.12 bits
Determine how many bits in 1 character:
x \u003d https://pandia.ru/text/79/128/images/image013_32.gif "width \u003d" 51 "height \u003d" 21 "\u003e,
N \u003d 256 characters in the alphabet
In the alphabet of some formal language there are only two letters. Each word of this language necessarily consists of 7 letters. What is the maximum number of words that can be written in this language?Since only 2 characters are used for writing words, with N-movements there are different sets of words .. gif "width \u003d" 147 "height \u003d" 21 "\u003e
Let us bring the expression to a common base and common units of measurement.
https://pandia.ru/text/79/128/images/image018_25.gif "width \u003d" 119 height \u003d 21 "height \u003d" 21 "\u003e
We solve the equation:
5 (x + 3) \u003d 8x + 20
5x + 15 \u003d 8x + 20
5x - 8x \u003d 20 - 15
How much information does the screen carry?SVGA - monitor (16-bit coding, screen size 800 * 600)?Let's determine how many pixels are in the whole screen:
800 * 600 \u003d pixel
* 16 bits \u003d 7 bits \u003d bytes \u003d 937.5 KB \u003d 0.9 MB
How many colors does a picture with a size of 100 * 150 pixels and a volume of 29.3 Kb contain
- it turns out that 1.7 times more is given, then there is enough video memory!But if you need the source code, all the topics that are discussed on this page, then all this can be downloaded in one archive!
If you can’t download, then see
Warning:
You can’t stupidly roll this lesson and get five!
Requirements and views on the assignment for each teacher are different.
Before continuing, this one was made on this principle, as described below ... And by the way, this design was made in 2008 ...
There is no content on the pages, a simple description of the process, what is responsible for. You need to come up with something, meaning filling, using the functionality of this archive!
Computer science task - “create your own website”
The task:
Create a site of at least 7 pages.
Mandatory use of tables.
Use CSS.
Insert a photo on one of the pages.
On one of the pages use Java script.
On pages use text formatting, paragraph, indent, numbered list.
Download the task of computer science "create a site."
Where will we make the site?
Not only an assignment in computer science, but also useful information for anyone interested in how to make a website on their own.
You can make a site that will be located on your PC with links to pages in a folder.
We will create from the very beginning.
The first page of the site is called index.html
Create a folder where our site will be stored.
Open the notebook, copy the code from here and paste it into the notebook:
The page is ready!
Create a table on the job page on computer science:
(Tag Designed to display GIF, JPEG, or PNG image files on a web page. This tag has the only required src attribute that defines the address of the image file.)
This line tells us that our drawing is called logotip.JPG with a size of 500 x 200
Attention:
image size must not exceed the width of the table!
Create an additional folder and name it - "foto"
Our line should be like that.
In order not to change the code, open any image that you want to see in the header of the page and save it as
If you want to resize the logo, then on the top line
resize the image to yours. (this is necessary for the correct display of your logo).
width \u003d "500" height \u003d "200"
Background on the computer science assignment page:
This is not part of the task, but it will be a very boring page if we do not put the image in the background.
Add to the line