Coding and Decoding

In all aptitude tests, coding decoding is an integral aspect of the Logical Reasoning portion. This guide will help you understand them properly.

Coding is the process of encrypting a word, a number, or a pattern in a certain pattern or code based on the rules which are set.

The process of decrypting a pattern into its original form from provided codes is known as decoding.

Coding and Decoding Types

In competitive examinations, you will encounter several sorts of coding and decoding problems. Few of the most prevalent varieties are listed below:

Coding from Letter to Letter

In this technique of coding and decoding, the letters of the word are coded utilizing different operations including subtraction, addition, interchanging, and many more. Candidates must decode or change the code of other words using the same procedures.

Coding from Letters to Numbers

A term is assigned numerical code merit, or a number is allocated to alphabetically code letters, in this type of coding-decoding.

Substitutional Coding

In this type of coding-decoding, words are encrypted or coded with the relevant keyword.

Clock Coding

In this type of coding-decoding, numbers between 1 to 12 are coded, and inquiries are responded according to clock timing.

Binary Coding

In this type of coding-decoding, binary values such as 0 and 1 are utilised to encode decimal integers.

Conditional Coding

In this type of coding-decoding, a few methods will be taught, and applicants must apply all of the provided conditions to obtain the code of a certain word.

Letter Positions in the English Alphabet

Because a word or a sentence is coded by shifting the locations of English alphabet letters in a certain pattern, it’s important to memorise the positions of all the letters in English alphabetical order, both forward and backward.

EJOTY Technique

With the help of this basic principle, you may simply memorise the placements of alphabets and discover the placement of any letter without much effort. However, it is recommended that you master the alphabet’s letter positions.











Lets solve a Coding and Decoding Problem with the help of EJOTY technique. For example, we’re supposed to discover the 24th letter from the alphabet’s left side. We already know that the 25th letter from the left is Y; now we must locate the letter preceding Y, which is X. We can simply discover the location of any letter in the alphabet using this easy approach. It is necessary to memorise the places and sequence of letters in order to solve any problems.

Tips & Tricks For Coding-Decoding

This is vital to be aware of some methods that will assist you in swiftly salting questions throughout your preparation for the topic of coding-decoding. 

For more information, see the approaches listed below.

  • Begin by carefully accessing the question and jotting down all of the words, besides what is with their corresponding codes.
  • Attempt to figure out the pattern followed in the code you’ve been given. You may use the hit-or-miss strategy to look for numerous rules.
  • The elimination procedure can also be used to streamline the quotation and eliminate any unneeded values.
  • It’s worth noting that coding-decoding issues can be addressed in several ways.
  • You will benefit from answering plenty of questions as you prepare.

Coding & Decoding Question And Answers

Q.1 If the decoded value of ‘FROZEN’ is ‘OFAPSG’. Select the correct option that shows ‘MOLTEN’ written in this manner.

  2. OFSMPN 
  3. OFUMPN 
  5. OFUMON   


To answer this question, simply invert the word and add one to each letter. NETLOM is the alphabetically opposite of MOLTEN. The code for MOLTEN becomes OFUMPN if we add 1 to each letter.

So ans is (c)  

Q.2 HARYANA is written as 8197151 in a certain code; how is DELHI written in that code?

  1. 44585
  2. 45389
  3. 54679
  4. 75850


We utilised the number of alphabets as a solution.

H = 8

A = 1

R = 18 = 1+8 = 9

Y = 25 = 2+5 = 7


D = 4

E = 5

L = 12 = 1+2 = 3

H = 8

I = 9 

As a result, DELHI is abbreviated as b) 45389.

Q.3 If January is called “March”, March is called “April” and April is called “May”, then which of the listed months will have only 30 days?

  1. January
  2. March
  3. April
  4. May


January, March and May have 31days and April has 30 days.But April is called May so the answer is (d) May.

So that’s how Coding and Decoding Questions are solved.


Coding-decoding encompasses all areas of learning and aims to improve children’s logical thinking abilities as well as their capacity to recognise distinct sounds that makes up words. Coding-decoding aids in the development of children’s fluency, vocabulary, understanding, and exposure to phonemic terms.

Coding-decoding aids in the understanding of how communication occurs. There are several types of coding-decoding that may be used to learn how to match patterns with numbers, symbols, and letters. The reasoning booster for improving reading abilities and comprehension is coding-decoding.