Coding-Decoding Questions for RRB NTPC: Download Free PDF & Practice Now

Preparing for the RRB NTPC exam? You know that the General Intelligence and Reasoning is one of the best sections to score high marks. Unlike Math, you don’t need long calculations. Unlike GK, you don’t need to memorize dates. Still, most candidates fail to score good marks in this section because they don’t prepare the most scoring topics. One of the most popular topics in Reasoning is Coding-Decoding.

At first glance, seeing a question like “If DELHI is coded as CCIDD, how is BOMBAY coded?” might look like a secret spy message. But don’t worry. You don’t need to be James Bond to solve this.

Here is the secret: Coding-Decoding is just a game of patterns. The examiner simply shifts letters forward or backward (like A becomes B, or A becomes Z). Once you understand the rule, you can solve these questions in 10-15 seconds. To help you master this topic, we have collected the most repeated Coding-Decoding questions from previous Railway exams. We have compiled them into a free PDF that you can download from this blog.

Why is Coding-Decoding Important for RRB NTPC?

In both CBT-1 and CBT-2, this topic is a goldmine for marks.

• High Weightage: You can expect 3 to 5 questions in every shift. That is a lot of marks for one topic!
• Easy Logic: The logic is usually simple (+1, -1, or Reverse). Railway exams rarely ask very complex coding questions.
• Time Saver: If you know the position of letters (like A=1, T=20), you can solve these faster than any other question.

Important Types of Coding Questions

You will mostly see three types of questions in the exam:

1. Letter Coding: Replacing letters with other letters. (Example: CAT -> DBU)
2. Number Coding: Replacing letters with numbers. (Example: A=1, CAT=24)
3. Mixed Coding: Coding sentences. (Example: ‘pit na som’ means ‘bring me water’)

Download Free PDF of Coding-Decoding Questions for RRB NTPC

We have analyzed many previous years’ question papers to understand the types of questions RRB asks in the exam. After carefully analysing those papers, we have created a PDF in which we have provided the most repeated, asked, and exam-level questions. You can download this PDF for free and start practicing for the exam.

Q1. In a certain code, ‘TEACHER’ is written as ‘VGCEJGT’.
How is ‘CHILDREN’ written in that code?

(a) EJKNFTGP
(b) EJKNFGTO
(c) EJKNEGTP
(d) EJKNFTGO

Answer: (a) EJKNFTGP

Logic:
Each letter is shifted +2 in the alphabet.
T + 2 = V, E + 2 = G, A + 2 = C …
Similarly, C + 2 = E, H + 2 = J, I + 2 = K, L + 2 = N, D + 2 = F, R + 2 = T, E + 2 = G, N + 2 = P.

Q2. If ‘RACKET’ is written as ‘813524’, how is ‘TRACK’ written in that code?

(a) 24138
(b) 42138
(c) 41238
(d) 21438

Answer: (b) 42138

Logic:
Direct letter coding based on RACKET:
R = 8, A = 1, C = 3, K = 5, E = 2, T = 4.
So, TRACK = T R A C K = 4 2 1 3 8 → 42138.

Q3. If Z = 52 and ACT = 48, then BAT will be equal to:

(a) 39
(b) 41
(c) 44
(d) 46

Answer: (d) 46

Logic:
Z = 26 × 2 = 52
ACT = (1 + 3 + 20) × 2 = 24 × 2 = 48
BAT = (2 + 1 + 20) × 2 = 23 × 2 = 46

Q4. If ‘WATER’ is written as ‘YCVGT’, then what is written as ‘HKTG’?

(a) IRFE
(b) FIRE
(c) REFI
(d) ERIF

Answer: (b) FIRE

Logic:
Each letter is shifted +2.
To decode, shift –2:
H – 2 = F, K – 2 = I, T – 2 = R, G – 2 = E → FIRE

Q5. In a certain code language:
‘134’ means good and tasty
‘478’ means see good pictures
‘729’ means pictures are faint

Which digit stands for ‘see’?

(a) 9
(b) 2
(c) 1
(d) 8

Answer: (d) 8

Logic:
‘Good’ appears in first and second → common digit = 4
‘Pictures’ appears in second and third → common digit = 7
In ‘478’, remaining word is ‘see’ → remaining digit = 8

Q6. If ROSE is coded as 6821, CHAIR as 73456, and PREACH as 961473, what will be the code for SEARCH?

(a) 246173
(b) 214673
(c) 214763
(d) 216473

Answer: (b) 214673

Logic:
Direct letter coding:
S = 2, E = 1, A = 4, R = 6, C = 7, H = 3
SEARCH = 214673

Q7. If A = 26 and SUN = 27, then CAT = ?

(a) 24
(b) 27
(c) 57
(d) 58

Answer: (c) 57

Logic:
Reverse alphabet values (A = 26, Z = 1)
SUN → S = 8, U = 6, N = 13 → 8 + 6 + 13 = 27
CAT → C = 24, A = 26, T = 7 → 24 + 26 + 7 = 57

Q8. In a certain code, ‘MONKEY’ is written as ‘XDJMNL’.
How is ‘TIGER’ written in that code?

(a) QDFHS
(b) SDFHS
(c) SHFDQ
(d) UJHFS

Answer: (a) QDFHS

Logic:
First reverse the word, then subtract 1 from each letter.
MONKEY → YEKNOM → XDJMNL
TIGER → REGIT → QDFHS

Q9. If:
SKY is called SEA,
SEA is called WATER,
WATER is called AIR,
AIR is called CLOUD,
CLOUD is called RIVER,

Where do we fly an aeroplane?

(a) WATER
(b) CLOUD
(c) AIR
(d) RIVER

Answer: (b) CLOUD

Logic:
We fly an aeroplane in AIR, but AIR is called CLOUD.

Q10. If E = 5 and HOTEL = 12, then how will you code LAMB?

(a) 7
(b) 10
(c) 26
(d) 28

Answer: (a) 7

Logic:
HOTEL → (8 + 15 + 20 + 5 + 12) = 60
Number of letters = 5 → 60 ÷ 5 = 12
LAMB → (12 + 1 + 13 + 2) = 28
Number of letters = 4 → 28 ÷ 4 = 7

How to Prepare for Coding-Decoding Easily?

Here, we have provided some tips and tricks to solve coding-decoding questions easily in the exam.

• Learn EJOTY: This is the best trick. Remember E-J-O-T-Y corresponds to 5-10-15-20-25. If you need to find ‘T’, you know it’s 20 instantly. If you need ‘S’, it’s just before T, so 19.
• Write A to Z: As soon as you get your rough sheet in the exam hall, write A to M in one line and N to Z right below it (backwards). This helps you find Opposite Pairs (like A-Z, B-Y, C-X) instantly.
• Check the First and Last: Don’t solve the whole word. Check the code for the first and last letter. Usually, you can find the correct option just by that.
• Practice Daily: Solving 10 questions a day keeps the logic fresh. Use our Free Topic Tests to challenge yourself.

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