Coding-Decoding with Basic Concepts and Examples

0
1379

Coding-Decoding with Basic Concepts and Examples

Coding-Decoding with Basic Concepts and Examples. Today we are presenting you the basic concepts of coding-decoding with examples. Usually 3-5 questions in Coding-Decoding are asked often in question papers.

Coding is a method of transmitting a message between the sender and the receiver without a third person knowing it. Before transmitting, the data is encoded and at receiver side, the encoded data is decoded in order to obtain original data by determining common key in the encoded data.

We we show you several common types of problems asked in Coding and Decoding and the methods to solve them.

Approach to Answer Questions on Coding-Decoding

  • Observe alphabets or numbers given in the code keenly.
  • Find the sequence it follows, whether it is ascending or descending.
  • Detect the rule in which the alphabets/numbers/words follow.
  • Fill the appropriate letter/number/word in the blank given.

Types of Coding-Decoding Problems

There are four types of coding-decoding problems.

  • Letter Coding
  • Word Substitution
  • Mixed Letter Coding
  • Mixed Number Coding

Letter Coding

In this type alphabets in a word are replaced by certain other alphabets according to a specific rule to form its code. The candidate is required to detect the common rule and answer the questions accordingly.

Question
In a certain code, ‘CODING’ is written as ‘DPEJOH’. How will ‘DECODING’ be written in that code?

Answer
“DECODING” is “EFDPEJOH”
You will simple methods and examples to solve Letter Coding problems.

Some Basics which we need to learn before solving the questions of this topic are:
  1. Letter position (A=1, B=2, C=3, D=4 ……. Y=25, Z=26)
  2. Opposite position of letters (A=26, B=25 …… Z=1)
  3. Opposite of each letter (A is opposite to Z and B is opposite to Y and C is opposite to X ….. and so on Pairs AZ, BY, CX and so on are called corresponding letters .

Coding-Decoding Type of Letter Coding

In this type alphabets in a word are replaced by certain other alphabets according to a specific rule to form its code. The candidate is required to detect the common rule and answer the questions accordingly.

Question
In a certain code, “CODING” is written as “DPEJOH”. How will “DECODING” be written in that code?

Answer
Compare 1st letter of CODING with 1st letter of DPEJOH.
C is converted to D.
You know C’s next letter in alphabets is D.
O’s next letter is P.
D’s next letter is E.
I’s next letter is J.
N’s next letter is O.
G’s next letter is H.
This was how CODING was converted to DPEJOH. Now in the same way you have to convert DECODING.
So DECODING should be converted to EFDPEJOH.

Example: Letter Coding

Question
In a certain code language, ‘PICTURE’ is written as ‘QHDSVQF’. How would ‘BROWSER’ be written in that same code language?

Answer
Clearly, the letters in the word ‘PICTURE’ are moved alternately one step forward and one step backward to obtain the letters of the code. Thus, we have

Coding-Decoding with Basic Concepts and Examples

Example: Letter Coding

Question
In a certain code language, ‘BAT’ is written ‘YZG’. How will ‘SICK’ be written in that same code?

Answer

Coding-Decoding with Basic Concepts and ExamplesWord Substitution

In this type a word is replaced by certain other word according to a specific rule to form its code. The candidate is required to detect the common rule and answer the questions accordingly.

Question
If ‘white’ is called ‘blue’, ‘blue’ is called ‘red’, ‘red’ is called ‘yellow’, ‘yellow’ is called ‘green’, ‘green’ is called ‘black’, ‘black’ is called ‘violet’ and ‘violet’ is called ‘orange’, what would be the colour of human blood?

Answer
The colour of the human blood is ‘red’, and as it is given that ‘red’ is called ‘yellow’. So, the colour of human blood is ‘yellow’

Example: Word Substitution

Question
If ‘Parrot’ is known as ‘Peacock’, ‘Peacock’ is known as ‘Swallow’, ‘Swallow’ is known as ‘Pigeon’ and ‘Pigeon’ is known as ‘Sparrow’, then what would be the name of Indian National Bird?

Answer
We know Peacock is the Indian National Bird. But here Peacock is known as Swallow. So the answer is Swallow.

Mixed Letter Coding

In Mixed letter coding type of questions, three or four complete messages are given in the coded language and the code for a particular word is asked.

Coding – Decoding Types of Mixed Letter Coding

In Mixed letter coding type of questions, three or four complete messages are given in the coded language and the code for a particular word is asked.

The general approach to answer these problems are as follows

  • To analyse such codes, any two messages bearing a common word are picked up.
  • The common code word will mean that word.
  • Proceeding similarly by picking up all possible combinations of two, the entire message can be analysed.

Example: Mixed Letter Coding

Question
In a certain code language,
1. ‘pod na joc’ means ‘very bright boy’;
2. ‘tam nu pod’ means ‘the boy comes’;
3. ‘nu per ton’ means ‘keep the doll‘;
4. ‘joc ton su’ means ‘very good doll’.
Which of the following means ‘bright’ in the same code language?

Answer
In statements (a) and (b), the common code word is ‘pod’ and the common word is ‘boy’. So, ‘pod’ stands for ‘boy’.
In statements (a) and (d), the common code word is ‘joc’ and the common word is ‘very’. So, ‘joc’ stands for ‘very’.
So, in (a) ‘na’ stands for ‘bright’.

Example: Mixed Letter Coding

Question
In a certain language, ‘sun shines brightly’ is written as ‘ba lo sul’, ‘houses are brightly lit’ as ‘kado ula ari ba’ and ‘light comes from sun’ as ‘dopi kup lo mo’. What are the code words for ‘sun’ and ‘brightly’?

Answer
sun shines brightly ⇒ ba lo sul → (i)
houses are brightly lit ⇒ kado ula ari ba → (ii)
light comes from sun ⇒ dopi kup lo mo → (iii)
Comparing Equations. (i) and (ii), we get brightly → ba
From Equations. (i) and (iii), sun → lo

Mixed Number Coding

In this type of questions, a few groups of numbers each coding a certain short message, are given. Through a comparison of the given coded messages, taking two at a time, the candidate is required to find the number code for each word and then formulate the code for the message given.

Example: Mixed Number Coding

Question
In a certain code, ‘786’ means ‘study very hard‘,
‘958’ means ‘hard work pays’
‘645’ means ‘study and work’.
Which of the following is the code for ‘very’?

Answer
In the first and second statements, the common word is ‘hard’ and the common code digit is ‘8’. So, ‘8’ means ‘hard’.
In the first and third statements, the common word is ‘study’ and the common code digit is ‘6’. So, ‘6’ means ‘study’.
Thus, in the first statement ‘7’ means ‘very’.

Example: Mixed Number Coding

Question
If ‘WORK’ is coded as ‘4-12-9-16’, then in the same code language how will you code ‘WOMAN’?

Answer
Here, each letter is coded by the numerical obtained by subtracting its ‘position value’ in English alphabet, from 27, e. g.,W, O, M, A, N are 23rd, 15th, 13th, 1st and 14th letters. So, their codes are (27 – 23), (27 – 15), (27 – 13), (27 – 1), (27 – 14), i.e., 4, 12, 14, 26, 13,

Coding-Decoding with Basic Concepts and Examples

Stay Tuned, Stay Updated. Visit Again.