Coding – Decoding
Coding – Decoding is
process of transmitting an information from one place to other using some
suitable codes, so that it might reach to other person safely. Coding –
Decoding of an information is done with various rules or patterns, so that only
the right person can decipher it.
Ø Coding Based on
Rearrangement of Letters
Ø Coding based on
Replacement of Letters
Ø Opposite Letters
Coding
Ø Coding of Letters by
their Left and Right Letters
Ø Number Coding
Ø Symbol coding Based on
Similarity
Ø Coding by
Substitution/ Word Replacement
Ø Fictitious Language
Coding
Ø Coding by Comparison
Ø Conditional Coding
Ø Matrix Coding
Coding
When any letter/ word/
sentence is written or said in such a language which hides the actual meaning
of that particular letter/ word/ sentence from others except the desired
person.
Decoding
It helps in tracing
out the actual meaning of a coded letter/ word/ sentence. Generally, coding is
done on the basis of the letters of English alphabet and their corresponding
position.
In these questions, a
word (basic word) is coded in a particular way and candidates are asked to code
other words in the same way. As the matter of fact, there exists no uniform and
particular type or category of these questions according to which we could
classify questions of coding –decoding. However, keeping in view the
candidate’s convenience, we have classified different types of questions with
illustrations and explanations under different headings. To solve the questions
based on coding- decoding, first of all it is necessary to remember the
positions of all alphabetical letters, both in forward and backward order.
Several ways for easy remembering of these positions are discussed here.
Forward Order Position (Left to Right)
Forward order
positions of letters can be remember in the following ways.
(i) Here is a gap of
four letters between each letter of the word group ‘EJOTY’.
ð
EJOTY
sounds
like a girl name that is JOTI, so it could be remembered by this name.
(ii) Here is a group
letters between each letter of the word group ‘CFILORUX’.
ð
CFILORUX
sounds
like an injection name because the
injections which are prescribed by doctors are having strange names.
Backward Order Position (Right to left)
Students find it
difficult to remember backward order positions but, if they keep forward order
positions of letters in their mind, they can easily calculate the backward
order position of letters in the following way
ð Backward order
position of any letter = 27 – forward order of that letter
Backward
order position of A = 27 – forward order position of A =27 -1 =26
Opposite Letters
These are called
opposite letters as the forward order corresponding position of an opposite
letter is as same as the backward order corresponding position of its opposite
letter.
1 2 3 4 5 6 7 8 9 10 11 12 13
↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨
A B C D E F G H I J K L M
26 25 24 23 22 21 20 19 18 17 16 15 14
↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨ ↨
Z Y X W V U T S R Q P O N
A and Z is a pair of
opposite letters.
The pair of opposite
letters can easily be remembered in following ways.
(i) A Z(Aaza) (ii)
B Y(By) (iii)
C X(Six) (iv)
D W(Dew) (v)
E V(Evening)
↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
1+26 =27 2+
25=27 3+ 24=27 4 +23=27 5 + 22 =27
(vi) F U(Uff) (vii)
G T(GT Road) (viii) H S(High School) (ix)
I R(Indian Railways)
↓ ↓ ↓
↓ ↓
↓ ↓ ↓
6 +21 =27 7+ 20 =27 8 +19=27 9 +18=27
(x) J Q(Jack Queen) (xi) K P(Kevin
Peterson) (xii) L O(Lover) (xiii)
M N(Man)
↓ ↓ ↓ ↓ ↓
↓ ↓ ↓
10+ 17 =27 11+ 16=27 12 +15 =27 13+ 14=27
Arrangement of Letters
Letters of English
alphabet can be arranged either in liner form or in circular form as shown
below.
1. Linear Arrangement (Straight Line
Arrangement)
(i) Left to Right:-
(ii) Right to Left: -
2. Circular Arrangement
(i)
Clockwise Arrangement
(ii) Anti-clockwise Arrangement
Understanding of linear and circular
arrangement is very important as when, we have to find the letters forward or
backward within the limit of 26 letters of English alphabet, we can use linear
arrangement but when we have to find the letters before A or after Z, then circular
arrangement is very- very useful.
If we have to find the letter one place
forward to A, then that letter will be B and this result can be found out by
using either linear or circular arrangement but when one is asked to find the
letter which is one letter backward of A (Z is one letter backward of A) or one
letter forward of Z (A is one letter forward of Z), they only circular
arrangement gives such result.
Letter Coding
In this type of question, the letters of
a certain word are arranged in different orders which can be reverse order or
fragmented order. The candidates are therefore to understand the different
patterns of the letter coding and solve different types of problems based on
these patterns which are discussed below.
Type 1.
Coding Based on Rearrangement of Letters
In this type of
coding, the letters of the original word are rearrangement in a particular
manner to obtain the code. Such coding can be of following types.
(i) When all the
letters of a word are written in reverse order.
Ex: if in a certain code
language ‘RAMESH’ is written as ‘HSEMAR’, then how will ‘CREATE’ be written in
that language?
(a) TEACRE (b) ETAECR (c)
ETAERC (d) ETACRE
Solution:(c)
(ii) When letters of
the word are divided into two parts and then both the parts are written in
reverse order or the first part is written in reverse order at the place of
second part and second part is written in reverse order at place of first part.
Following situations
can arise in such cases.
(a) When the number
of letters of the word is even
Coding of A B C D E F
1 2 3 4 5 6
7 can be done in certain ways as follows.
Ex: if in a certain code
language ‘THREAT’ is written as ‘RHITTAE’, then how will ‘PEARLY’ be written in
that code?
(a) YLRAEP (b) YLRPAE (c)
AEPYLR (d) AEPRLY
Solution: (c)
As,
PEARLY = AEPYLR
(b) When the number
of letters of the word is odd
Coding of A B C D E
1 2
3 4 5 can be done in certain ways
as follows
Ex: If in a certain code
language ‘GREAT’ is written as ‘GRETA’,
then how will ‘FIGHT’ be written in that code?
(a) FIGHT (b) FGITH (c)
FGIHT (d) FITGH
Solution: (a)
FIGHT
= FIGTH
(c) When letters of
the word are divided into two or more groups and then all or some particular
groups are written in reverse order.
Coding
of A B C D E F
1 2 3
4 5 6 can be done in certain ways as
follows
Ex: If in a certain code
language ‘SECTOR’ is written as ‘ESCTOR’, then how will ‘MOTHER’ be written in
that code?
(a) MOTHER (b) OMHTER (c)
OMHTRE (d) OMTHER
Solution:(d)
As, 
MOTHER
=OMTHER
(d) When first and
last letter of the word remain at the same place but middle letters get
reversed
Ex: If in a certain code
language ‘SECTOR’ is written as ‘SOTCER’, then how will ‘MOTHER’ be written in
that code?
(a) MTOHER (b) MEHTOR (c)
MEHOTR (d) METOHR
Solution: (b)
As, 
(e) When each
letter of the word is written at a certain place
Coding of A B C D E
1 2 3 4
5 can be done in certain ways as follows
Ex: If in a certain code
language ‘MIGHT’ is written as ‘GHMTI’, then how will ‘EARTH’ be written in
that code?
(a) RTEHA (b) RTEAH (c)
RTAEH (d) RETHA
Solution: (a) 
As,
EARTH
= RTEHA
Are you preparing for Government Job and you want to crack them? If Yes, you have reached on right place. I, Vaishali Jain, a content developer and Post Graduate from Commerce, Belongs to U.P. I like to help students. Here we are providing you the best material for Bank, SSC, Railway and other Competitive Exams.
ConversionConversion EmoticonEmoticon