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SSC CGL Exam (Tier-I): Reasoning: Coding-Decoding: Concepts & Free Online Practice Set

Staff Selection Commission will be conducting Combined Graduate Level Exam for the recruitment to the different Group ‘B’ and Group ‘C’ posts. Jagranjosh.com has come up with SSC CGL Exam (Tier-I): Reasoning: Coding-Decoding: Concepts & Free Online Practice Set. Candidates should include these questions in their course of study. Here, we provide concepts along with Free Online Practice Set to make the easo of students in cracking Coding-Decoding questions in exam.

 Concepts: Coding Decoding

Coding Decoding test is to judge a candidate’s ability to decipher the code language. Coding is the process of converting a word into another language by using letters and numbers while decoding is to convert the coded value back into the normal language. In each question of this topic a word and coded form of the word will be given to the student. A student will required to decode the logic behind this coding and then apply the logic to another given word to find the answer in form of a code.

English alphabets and their corresponding number values helps the candidate to increase the performance in this area. The position of the letter in the English Alphabet is considered to be the value of the alphabet in questions on letter series. Also, when we are counting from A to Z, we again start with A, i.e. we treat the letters as being cyclic in nature. While attempting the letter series one should know the value of each of the alphabet as

Alphabets in natural series are:


The Word EJOTY is very helpful in finding the position of the alphabet as

E      JOT            Y
5      101520          25

For example, if we want to find the position of the alphabet ‘S’, then as we know that ‘T’ is 20, so ‘S’ is 20 – 1 = 19. Also, we can find the position of an alphabet from the end by subtracting its value from 27. For example, the position of D from the end is 27 – 4 = 23.

The pattern below is very useful to find many types of question in Alphabet Series when we write the last 13 alphabets in front of the first 13 alphabets of the English:


The questions on coding and decoding are basically of three types as given below.


1. In a certain code ‘SHIMLA’ is written as ‘RGHLKZ, how will PATNA be coded then?


Sol: Each letter is coded as the letter previous to it, i.e. S = R, H = G, I = H, M = L, L = K, A = Z. PATNA will become OZSMZ. Hence the answer is (b)

2. If CEJQ is coded as XVQJ, then BDIP will be coded as :


Sol: The first 13 letters of the alphabet are coded by the 13 letters of the alphabet in reverse, i.e.

= A B C D  E F G H I  J  K  L M (first 13 letters)

= Z Y X W V U  T S R Q P O N (13 letters in reverse)

It is obvious from the above coding scheme that :

B = Y, D = W, I = R and K = P or P = K

Therefore, B D I P will be coded as Y W R K.

So, the answer is (b).


3. If LODES is coded as 46321, how will you code the word DOES?

a) 1234 b) 4321 c) 3621 d) 3261

Sol: Here, you will observe that all the letters of DOES are included in the letters of LODES, for which you have the code D = 3, O = 6, E = 2, S = 1. Therefore DOES = 3621. So, the answer is (d).

4. DAZE is written as 41265 in a certain code. How will BOY be written in the same code?

a) 41425 b) 5120 c) 21525 d) 359

Sol: In this question the position of each alphabet is given like D is 4 , Z is 26 etc. So the Code of BOY will be 21525 as B is 2, O is 15 and Y is 25. So, the answer is (c)


5. In a certain code ‘415’ means ‘milk is hot’; ‘18’ means ‘hot soup’; and ‘895’ means ‘soup is tasty’. What number will indicate the word ‘tasty’?

a) 9 b) 8 c) 5 d) 4

Sol: The code for ‘hot’ is 1.So, the code of ‘soup’ is 8. Now the code of ‘is’ is 5. Hence we can say that the code of ‘tasty’ is 9. So, the answer is (a)

6. If ‘black’ is called ‘pink’, ‘pink’ is called ‘blue’, ’blue’ is called ‘brown’, ‘brown’ is called ‘orange’, ‘orange’ is called ‘violet’, ‘ violet’ is called ‘red’ and ‘red’ is called ‘black’, what is the colour of blood ?
a) black b) brown c) pink d) orange

Sol: As the colour of blood is red and red is called black in the given coded language. So the colour of blood is black in the given coded language. So the answer is (a)


[Source:- Jagranjosh]

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