Coding and decoding for SSC bank and railway exam with tips and trick

Many of the SSC & Railway exams are about to begin and Coding-Decoding is considered as an important topic in Exams. Below given are some essential tips & tricks to solve coding-decoding questions. These tips will help you score more in the upcoming exams. The CODING-DECODING test is given to judge the candidate's ability to decipher the rule which is applied for coding a particular message and break the code to reveal the message. Coding and Decoding forms a dedicated part of the Reasoning Section in various competitive exams but the level of questions differs in them. In order to have a clear insight into the questions on Coding-Decoding, it is better to discuss each type of questions separately.

What is the approach to solving the questions of this section?

• 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.

Types of Coding - Decoding

Type 1: Letter Coding.

Type 2: Number Coding.

Type 3: Substitution.

Type4: New Type of Coding

Detailed Explanation 

Type 1: Letter Coding:

In this type, the real 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.

Case1: To form the code for another word

If in a certain language MYSTIFY is coded as NZTUJGZ, how is NEMESIS coded in that language?

Sol. Clearly, each letter in the word MYSTIFY is moved one step forward to obtain the corresponding letter of the code.

M Y S T I F Y

+1↓

N Z T U J G Z

So, in NEMESIS, N will be coded as O, E as F, M as N and so on. Thus, the code becomes OFNFTJT.

Case 2: To find the word by analyzing the given code (DECODING)

If in a certain language CARROM is coded as BZQQNL, which word will be coded as HOUSE?

SOL: each letter of the word is one step ahead of the corresponding letter of the code

B Z Q Q N L H O U S E

+1↓

C A R R O M I P V T F

So, H is coded as I, O as P, U as V, S as T and E as F. HOUSE is coded as IPVTF.

Type 2: NUMBER CODING

In these questions, either numerical code values are assigned to a word or alphabetical code letters are assigned to the numbers. The candidate is required to analyse the code as per the directions.

Case 1: When numerical code values are assigned to words

If in a certain language A is coded as 1,B is coded as 2, and so on, how is BIDDIC is coded in that code?

SOL:

As given the letters are coded as

A B C D E F G H I

1 2 3 4 5 6 7 8 9

So in BIDDIC, B is coded as 2, I as 9,D as 4 and C as 3. Thus, BIDDIC is coded as 294493

Case 2: Number to letter coding.

In a certain code, 2 is coded as P, 3 as N, 9 as Q, 5 as R, 4 as A and 6 as B. How is 599423 coded in that code?

SOL: Clearly as given 5 is coded as R, 9 as Q, 4 as A, 2 as P, 3 as N. So, 599423 is coded as RQQAPN

Type 3: SUBSTITUTION

In this section an object names are substituted with different object names. We should carefully trace the substitution and answer given question.

For Example:

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 color of human blood?

Sol: The color of the human blood is ‘red’, and as it is given that ‘red’ is called ‘yellow’. So, the color of human blood is ‘yellow’.

Type 4: NEW TYPE OF CODING

This is a kind of coding recently included in the Reasoning section. In this type of questions either alphabetical code values are assigned to symbols or symbols are assigned to alphabets. The candidate is required to analyse the code as per direction.

For Example:

In a certain code ‘TOME’ is written as @ $ * ? and ARE is written as ‘ • £ ? ’ How can ‘REMOTE’ be written in that code?

Sol: From the data we have T=@, O=$, M=*, E=? and A=•, R=£, E=?

Hence REMOTE is coded as £ ? * $ @ ?

Some Useful Tricks:

Trick 1: Use EJOTY to remember position of alphabet (Total=26) in series.

Opposite position of letters (A=26, B=25 …… Z=1)

Opposite of each letter (A is opposite to Z and B is opposite to Y and C is opposite to X …… and so on)

Trick 2: The reverse order can be obtained by subtracting the position from 27 say

Example: Opposite of M = 13 is 27-13= 14 = Four-teen = N