Coding Decoding Reasoning (2026): Types, Tricks, and Solved Examples for All Exams

Coding decoding reasoning is one of the most scoring topics in every competitive exam in India. Whether you are preparing for SSC CGL, IBPS PO, RRB NTPC, CAT, or campus placements, you will find coding decoding reasoning questions in almost every paper. The best part is that once you learn the types and the tricks, you can solve each question in under 30 seconds.

This guide covers every type of coding decoding reasoning question with clear explanations, solved examples, exam-specific tips, and shortcuts that actually work under exam pressure.

Quick Answer

Coding decoding reasoning is a logical reasoning topic where a word, number, or sentence is transformed using a hidden rule, and you have to find the same rule to encode or decode a new word. The most common types are letter coding, number coding, substitution coding, reverse coding, and mixed coding. The key to cracking coding decoding reasoning is spotting the pattern quickly using EJOTY and alphabet position logic.

What Is Coding Decoding Reasoning

Coding decoding reasoning tests your ability to identify hidden patterns in words, numbers, or symbols. In every question, a rule is applied to transform something into a coded form. Your job is to:

• Identify the rule used to create the code
• Verify the rule works for every letter or word given
• Apply the same rule to find the answer for the new word

Two key definitions:

• Coding: Converting a word, number, or sentence into a different form using a fixed rule
• Decoding: Reversing that process to find the original word or meaning from the coded form

Why coding decoding reasoning appears in every exam:

• It tests both speed and accuracy at the same time
• It requires no formula memorization, only pattern spotting
• Questions can be solved in 20 to 30 seconds once the pattern is clear
• It distinguishes candidates who think logically from those who guess

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Exams Where Coding Decoding Reasoning Is Asked

Alphabet Position Chart: The Foundation of Coding Decoding Reasoning

Every coding decoding reasoning question involving letters depends on alphabet positions. Memorize this chart completely.

EJOTY Shortcut: The fastest way to find any letter’s position is to use anchor points. E=5, J=10, O=15, T=20, Y=25. Count forward or backward from the nearest anchor.

Example: What position is R? Nearest anchor is T=20. R is 2 before T. So R = 20 minus 2 = 18.

Opposite Letter Formula: The opposite of any letter = 27 minus its position. So opposite of A(1) = 27 minus 1 = 26 = Z. Opposite of M(13) = 27 minus 13 = 14 = N.

Opposite letter pairs to memorize:

| A-Z | B-Y | C-X | D-W | E-V | F-U | G-T | H-S | I-R | J-Q | K-P | L-O | M-N |

Types of Coding Decoding Reasoning

1. Letter Coding

Each letter in the word is shifted forward or backward by a fixed number of positions in the alphabet.

How to identify it:

• Check the first letter: if C becomes E, that is +2
• Confirm with the second letter: if the shift is also +2, the pattern is confirmed

Example: If CAT is coded as ECV, what is the code for DOG?

Pattern confirmed as +2. Apply to DOG:

Answer: FQI

Wrap-around rule: If Z(26) shifts +1, it wraps to A(1). If A(1) shifts minus 1, it wraps to Z(26). Never go beyond 26 or below 1.

2. Reverse or Opposite Letter Coding

Each letter is replaced by its opposite letter in the alphabet. A becomes Z, B becomes Y, C becomes X, and so on.

How to identify it: Add the position of the original letter and the coded letter. If the sum is always 27, it is the opposite coding.

Example: If WATER is coded as DZGVI, what is the code for FIRE?

Check: W(23) + D(4) = 27. Confirmed opposite coding.

Answer: URIV

3. Reverse Word Coding

The letters of the entire word are written in reverse order. No positional shift is applied.

How to identify it: Read the code backwards. If it spells the original word, it is reverse word coding.

Example: If DELHI is coded as IHLED, what is the code for MUMBAI?

MUMBAI reversed = IABMUM

Answer: IABMUM

4. Number Coding

Letters are replaced by numbers following a specific rule. The most common rule is direct alphabet position values.

Common number coding rules:

Example: If SUN is coded as 19-21-14, what is the code for MOON?

These are direct alphabet positions. M=13, O=15, O=15, N=14.

Answer: 13-15-15-14

Example: If CAT is coded as 24, what is the code for DOG?

CAT = C(3) + A(1) + T(20) = 24. This is sum of positions.

DOG = D(4) + O(15) + G(7) = 26.

Answer: 26

5. Substitution Coding (Sentence Coding)

In this type, entire words in a sentence are replaced by code words. Three or four coded sentences are given and you must identify which code word represents which original word.

How to identify it: Look for a word that appears in two or more sentences. Its code will be the word that appears in both coded sentences.

Example:

• “sky is blue” = “ra na la”
• “water is cold” = “pa na da”
• “blue ocean deep” = “la ta ka”

What is the code for “blue”?

• “blue” appears in sentence 1 and sentence 3
• “la” appears in both coded sentences 1 and 3
• Therefore “la” = “blue”

Answer: la

Step to solve any substitution coding question:

• Find the word asked in the question
• Locate every sentence where that word appears
• Find the code word that is common to all those coded sentences
• That common code word is your answer

6. Mixed Coding (Variable Shift)

Each letter in the word shifts by a different number. The shift itself follows a pattern like +1, +2, +3 or +1, minus 1, +1, minus 1.

How to identify it: When a fixed shift does not work for all letters, calculate the shift for each position separately and look for a pattern.

Example: If TEACHER is coded as UGDGMKY, what is the code for BIG?

Pattern: +1, +2, +3, +4… Apply to BIG:

Answer: CKJ

7. Symbol or Conditional Coding

Specific conditions are given. The coding rule changes based on properties of the letter, such as whether it is a vowel or consonant, or whether it appears at the start or end of the word.

Example rule: Vowels are coded as their position number. Consonants are coded as their opposite letter.

Apply to CAT:

Answer: X1G

How to approach: Read all conditions before starting. Mark vowels and consonants first. Then apply the correct rule to each letter one by one.

8. Matrix Coding

A grid or matrix is given with row and column headers. Each letter is located inside the matrix and coded using its row number followed by its column number.

Example matrix:

Code for CAT: C is at row 0, column 2 = 02. A is at row 0, column 0 = 00. T is at row 3, column 4 = 34.

Answer: 02-00-34

Rule: Always read row number first, then column number.

9. Jumbled or Rearranged Letter Coding

In this type, the letters of the word are not reversed and not shifted. They are rearranged in a specific position order. The same position order is applied to every word.

How to identify it: Reversing does not work. Fixed shift does not work. The coded letters are the same as the original letters but shuffled into a different order.

Example: If GIVE is coded as VIEG and OVER is coded as EVRO, what is the code for DISK?

Find the position pattern using GIVE and VIEG:

Pattern: Position order 3, 2, 4, 1. Verify with OVER:

O(1), V(2), E(3), R(4) rearranged as position 3,2,4,1 = E, V, R, O = EVRO. Confirmed.

Apply to DISK: D(1), I(2), S(3), K(4) rearranged as 3,2,4,1 = S, I, K, D.

Answer: SIKD

Shortcut tip: Always number each letter of the original word and each letter of the code. Then figure out which original position maps to which coded position. Apply that same mapping to the new word.

10. Place Value Coding (Right to Left Position)

In this type, letters are coded using their position from the right end of the alphabet instead of the left. So Z=1, Y=2, X=3 and so on going backwards.

Right to left position chart:

How to identify it: The coded numbers do not match normal left-to-right positions. Add the normal position and the coded number. If it always equals 27, it is right-to-left place value coding.

Example: If CAT is coded as 24-26-7, what is the code for DOG?

Check: C normal position = 3. Code = 24. 3 + 24 = 27. Right-to-left confirmed.

D right-to-left = 27 minus 4 = 23. O right-to-left = 27 minus 15 = 12. G right-to-left = 27 minus 7 = 20.

Answer: 23-12-20

Shortcut tip: Right-to-left position of any letter = 27 minus its normal left-to-right position. Same formula as opposite letter coding but the output is a number instead of a letter.

11. Double Shift Coding (Odd-Even Position Shift)

In this type, odd-positioned letters and even-positioned letters are shifted by different values. For example, letters at positions 1, 3, 5 shift by +2 while letters at positions 2, 4, 6 shift by minus 1.

How to identify it: A single fixed shift does not work for all letters. Calculate shifts separately for odd positions and even positions. If odd positions share one shift value and even positions share another, it is double shift coding.

Example: If MANGO is coded as OBPHN, what is the code for GRAPE?

Find shifts position by position:

Hmm, position 5 breaks the pattern. Re-examine. Positions 1,3 = +2. Positions 2,4 = +1. Position 5 (odd) should be +2: O(15)+2=Q but code shows N(14). This means the question uses +2 for positions 1,3 and +1 for positions 2,4 only. Verify with another example before applying.

Better confirmed example: If APPLE is coded as CQQNG, what is the code for MANGO?

Wait, position 3 odd should be +2 but shows +1. This means odd = +2 except position 3. Re-examine more carefully.

Clean confirmed example: If BOOK is coded as DPPL, what is the code for BALL?

Positions 2,3,4 all +1. Position 1 = +2. Pattern: first letter +2, all others +1.

Apply to BALL: B+2=D, A+1=B, L+1=M, L+1=M.

Answer: DBMM

Shortcut tip: When a single shift fails, write the shift value for every position. Group odd and even positions. If they show two different consistent values, you have found your double shift pattern.

12. Coded Inequalities or Symbol Substitution Coding

In this type, mathematical operators like plus, minus, multiply, and divide are replaced by symbols or letters. You are given the substitution key and asked to solve the equation or verify a statement.

How to identify it: The question gives a key like “A means plus, B means minus, C means multiply” and then asks you to evaluate an expression.

Example: If A means +, B means minus, C means multiply, D means divide, then what is the value of 10 A 5 B 3 C 2?

Replace symbols: 10 + 5 minus 3 x 2

Apply BODMAS: 10 + 5 minus 6 = 9

Answer: 9

Example 2: If $ means +, @ means minus, # means x, % means divide, which of the following is correct?

A) 16 % 4 # 3 $ 2 @ 1 = 13 B) 16 % 4 # 3 $ 2 @ 1 = 14

Replace: 16 divide 4 x 3 + 2 minus 1

BODMAS: 4 x 3 + 2 minus 1 = 12 + 2 minus 1 = 13

Answer: Option A is correct

Shortcut tip: Always substitute all symbols first, then apply BODMAS strictly. The most common mistake is ignoring BODMAS after substitution.

13. Input-Output Coding

In this type, a word or number passes through multiple steps of transformation. Each step applies a rule. You are shown the output at several steps and asked what the output looks like at a specific step.

How to identify it: The question shows Step 1, Step 2, Step 3 outputs and asks for Step 4 or Step 5. Words are rearranged, shifted, or reordered at each step.

Example:

Input: cat dog sun moon star

Step 1: star cat dog sun moon (last word moves to front)

Step 2: moon star cat dog sun (last word moves to front again)

Step 3: sun moon star cat dog (last word moves to front again)

What is Step 4?

Pattern: At every step, the last word moves to the front.

Step 4: dog sun moon star cat

Answer: dog sun moon star cat

Number-based input-output example:

Input: 12 36 45 18 27

Step 1: 18 12 36 45 27 (smallest number moves to front)

Step 2: 12 18 36 45 27 (smallest of remaining moves to front)

Step 3: 27 12 18 36 45 (wait, this does not follow. Let us use a cleaner example)

Cleaner example:

Input: 84 17 52 33 61

Step 1: 17 84 52 33 61 (smallest moves to position 1)

Step 2: 17 33 84 52 61 (second smallest moves to position 2)

Step 3: 17 33 52 84 61 (third smallest moves to position 3)

What does Step 4 look like?

Pattern: Numbers are being sorted in ascending order, one number per step.

Step 4: 17 33 52 61 84 (fourth smallest 61 moves to position 4)

Answer: 17 33 52 61 84

Shortcut tip: For input-output questions, always identify the transformation rule within the first two steps. Do not try to guess from one step alone. The rule is almost always one of these: sorting numbers, rotating words, shifting a specific word, or alternating between two patterns.

14. Binary or Numeric Base Coding

Letters or words are coded using binary numbers (0s and 1s) or other number base systems. This type is less common but appears in advanced competitive exams.

Example: If A=00001, B=00010, C=00011 (binary of position), what is the code for ACE?

A=1=00001, C=3=00011, E=5=00101

Answer: 00001-00011-00101

Try It Yourself: Practice Questions by Type

Attempt all questions on your own first. Answers are listed at the very end of this section.

Type 1: Letter Coding (Fixed Shift)

1. If CAT = ECV, what is the code for DOG?
2. If MANGO = OCPIQ, what is the code for APPLE?
3. If KING = NKPI, what is the code for QUEEN?
4. If ROSE = TQUG, what is the code for LILY?
5. If COLD = EQNF, what is the code for WARM?
6. If BALL = DCNN, what is the code for GAME?
7. If SUN = VXQ, what is the code for MOON?
8. If FISH = HKUJ, what is the code for BIRD?
9. If STAR = UVCT, what is the code for MOON?
10. If DESK = FGUM, what is the code for LAMP?

Type 2: Opposite Letter Coding

1. If WATER = DZGVI, what is the code for FIRE?
2. If CAT = XZG, what is the code for DOG?
3. If KING = PRMT, what is the code for LION?
4. If ROSE = ILHV, what is the code for LILY?
5. If BOLD = YLOW, what is the code for CALM?
6. If STAR = HGZI, what is the code for MOON?
7. If HARD = SZIW, what is the code for SOFT?
8. If JUMP = QFNK, what is the code for FALL?
9. If WIND = DRMS, what is the code for RAIN?
10. If MANGO = NZMTL, what is the code for GRAPE?

Type 3: Reverse Word Coding

1. If MANGO = OGNAM, what is the code for APPLE?
2. If CRICKET = TEKCRIC, what is the code for FOOTBALL?
3. If TIGER = REGIT, what is the code for LION?
4. If SCHOOL = LOOHCS, what is the code for COLLEGE?
5. If WATER = RETAW, what is the code for JUICE?
6. If BRIGHT = THGIRB, what is the code for SMART?
7. If PLANET = TENALP, what is the code for EARTH?
8. If MOBILE = ELIBOM, what is the code for LAPTOP?
9. If DANCE = ECNAD, what is the code for MUSIC?
10. If SILVER = REVLIS, what is the code for GOLDEN?

Type 4: Number Coding

1. If CAT = 3-1-20, what is the code for DOG?
2. If SUN = 19-21-14, what is the code for MOON?
3. If BALL = 2-1-12-12, what is the code for GAME?
4. If KING = 11-9-14-7, what is the code for QUEEN?
5. If ROSE = 18-15-19-5, what is the code for LILY?
6. If TABLE = 20-1-2-12-5, what is the code for CHAIR?
7. If MANGO = 13-1-14-7-15, what is the code for GRAPE?
8. If FIRE = 6-9-18-5, what is the code for WIND?
9. If BLUE = 2-12-21-5, what is the code for PINK?
10. If CAT = 24, what is the code for DOG? (Sum of positions)

Type 5: Substitution Coding

1. “sky is blue” = “ra na la” and “sea is deep” = “ma na pa”. What is the code for “is”?
2. “sun rises east” = “ka ta ra” and “moon rises west” = “sa ta ja”. What is the code for “rises”?
3. “dog is friendly” = “pa na ma” and “cat is smart” = “ba na da”. What is the code for “is”?
4. “books are useful” = “ra ba la” and “books are expensive” = “ra ba da”. What is the code for “books are”?
5. “she plays well” = “da ma ka” and “he plays badly” = “na ma ra”. What is the code for “plays”?
6. “red is colour” = “ja ta ra” and “blue is colour” = “ja ta pa”. What is the code for “colour”?
7. “fish swim fast” = “la ra na” and “fish eat less” = “la ka ba”. What is the code for “fish”?
8. “time is money” = “ra la ka” and “money is precious” = “na la ra”. What is the code for “money”?
9. “run fast now” = “ba da na” and “walk slow now” = “ka sa na”. What is the code for “now”?
10. “good work done” = “ra ka da” and “good result expected” = “ra la pa”. What is the code for “good”?

Type 6: Mixed or Variable Shift Coding

Pattern for all 10 questions: Each letter shifts by +1, +2, +3, +4 and so on based on its position in the word.

1. What is the code for CAT?
2. What is the code for SUN?
3. What is the code for BALL?
4. What is the code for KING?
5. What is the code for ROSE?
6. What is the code for DESK?
7. What is the code for LAMP?
8. What is the code for FISH?
9. What is the code for MANGO?
10. What is the code for WATER?

Type 7: Symbol or Conditional Coding

Rule: Vowels are coded as their alphabet position number. Consonants are coded as their opposite letter.

1. What is the code for CAT?
2. What is the code for SUN?
3. What is the code for DOG?
4. What is the code for MAN?
5. What is the code for BIG?
6. What is the code for RUN?
7. What is the code for FLY?
8. What is the code for MAP?
9. What is the code for WIN?
10. What is the code for JOY?

Type 8: Matrix Coding

Use this matrix for all 10 questions. Row number first, column number second.

1. What is the matrix code for CAB?
2. What is the matrix code for BAD?
3. What is the matrix code for HEN?
4. What is the matrix code for MAN?
5. What is the matrix code for PEN?
6. What is the matrix code for RAN?
7. What is the matrix code for LAP?
8. What is the matrix code for WIN?
9. What is the matrix code for YAK?
10. What is the matrix code for FIG?

Type 9: Jumbled or Rearranged Letter Coding

Pattern for all 10 questions: Position order is 3-1-4-2 (3rd letter, 1st letter, 4th letter, 2nd letter).

1. What is the code for GOLD?
2. What is the code for RAIN?
3. What is the code for FARM?
4. What is the code for LION?
5. What is the code for SHIP?
6. What is the code for JUMP?
7. What is the code for BOND?
8. What is the code for MILK?
9. What is the code for DARK?
10. What is the code for FAST?

Type 10: Place Value Coding (Right to Left)

Right-to-left position = 27 minus normal position.

1. What is the right-to-left code for CAT?
2. What is the right-to-left code for DOG?
3. What is the right-to-left code for SUN?
4. What is the right-to-left code for MOON?
5. What is the right-to-left code for KING?
6. What is the right-to-left code for ROSE?
7. What is the right-to-left code for BALL?
8. What is the right-to-left code for FISH?
9. What is the right-to-left code for STAR?
10. What is the right-to-left code for LAMP?

Type 11: Double Shift Coding

Pattern: Odd positions (1st, 3rd, 5th) shift +2. Even positions (2nd, 4th, 6th) shift +1.

1. What is the code for CAT?
2. What is the code for SUN?
3. What is the code for BALL?
4. What is the code for KING?
5. What is the code for ROSE?
6. What is the code for DESK?
7. What is the code for LAMP?
8. What is the code for FISH?
9. What is the code for MANGO?
10. What is the code for WATER?

Type 12: Coded Inequalities

Key: P means +, Q means minus, R means x, S means divide.

1. 10 P 5 Q 3 = ?
2. 12 S 4 R 3 = ?
3. 8 P 4 R 2 Q 6 = ?
4. 20 S 5 P 3 Q 2 = ?
5. 15 Q 3 R 2 P 4 = ?
6. 6 R 3 P 4 Q 2 = ?
7. 18 S 6 R 2 P 1 = ?
8. 5 R 5 Q 10 P 3 = ?
9. 24 S 4 Q 2 R 3 = ?
10. 7 P 3 R 2 Q 4 S 2 = ?

Type 13: Input-Output Coding

Rule: At every step, the last word moves to the front of the sequence.

Input: apple mango guava banana cherry

1. What is Step 1?
2. What is Step 2?
3. What is Step 3?
4. What is Step 4?
5. What is Step 5? (Final step)

Rule: At every step, the smallest number moves one position to the left.

Input: 45 12 78 33 56

6. What is Step 1?
7. What is Step 2?
8. What is Step 3?
9. What is Step 4?
10. What is Step 5?

Type 14: Binary Coding

Letters are coded as binary of their alphabet position (5-bit binary). A=00001, B=00010, Z=11010.

1. What is the binary code for CAT?
2. What is the binary code for SUN?
3. What is the binary code for DOG?
4. What is the binary code for HI?
5. What is the binary code for ACE?
6. What is the binary code for BIG?
7. What is the binary code for RUN?
8. What is the binary code for MAP?
9. What is the binary code for FLY?
10. What is the binary code for WIN?

Answers

Type 1: Letter Coding (all +2)

1. FQI 2. CRRNG 3. SWGIR 4. VQNA 5. YCTS 6. HBNF 7. PRPO 8. DJSE 9. PRPO 10. NBNQ

Type 2: Opposite Letter Coding

1. URHV 2. WLT 3. ORLM 4. OROE 5. XZON 6. NLLM 7. HLUG 8. UZOOW 9. IZRM 10. TIZKY

Type 3: Reverse Word Coding

1. ELPPA 2. LLABTOOF 3. NOIL 4. EGELLOC 5. ECIUJ 6. TRAMS 7. HTRAE 8. POTPAL 9. CISUM 10. NEDLOG

Type 4: Number Coding

1. 4-15-7 2. 13-15-15-14 3. 7-1-13-5 4. 17-21-5-5-14 5. 12-9-12-25 6. 3-8-1-9-18 7. 7-18-1-16-5 8. 23-9-14-4 9. 16-9-14-11 10. 26

Type 5: Substitution Coding

1. na 2. ta 3. na 4. ra ba 5. ma 6. ja or ta 7. la 8. ra 9. na 10. ra

Type 6: Mixed Shift (+1,+2,+3…)

1. DBW 2. UWQ 3. CEMO 4. LKRK 5. STXH 6. EFWY 7. MCOQ 8. GJWL 9. NBQTS 10. XGYHX

Type 7: Conditional Coding (vowels = position, consonants = opposite)

1. X-1-G 2. H-21-M 3. W-15-T 4. N-1-M 5. Y-9-T 6. I-21-M 7. U-O-B 8. N-1-K 9. D-9-M 10. Q-15-B

Type 8: Matrix Coding

1. 02-00-01 2. 01-00-03 3. 12-04-23 4. 22-00-23 5. 30-04-23 6. 32-00-23 7. 21-00-30 8. 42-12-23 9. 44-00-21 10. 11-12-11

Type 9: Jumbled Coding (order 3-1-4-2)

1. LGOD 2. IARN 3. RАФM → RAFM 4. OINL 5. IHSP 6. MJUP 7. NBOD 8. LMIK 9. RDAK 10. SFAT

Type 10: Place Value Coding (27 minus position)

1. 24-26-7 2. 23-12-20 3. 8-6-13 4. 14-12-12-13 5. 16-18-13-20 6. 9-12-8-22 7. 25-26-15-15 8. 21-18-9-19 9. 8-7-26-9 10. 15-26-14-16

Type 11: Double Shift (odd +2, even +1)

1. EBV 2. WVO 3. CBNO 4. NLQI 5. TPUG 6. FETL 7. NBOP 8. HJUJ 9. OBPHN 10. YBVFS

Type 12: Coded Inequalities

1. 12 2. 9 3. 10 4. 5 5. 13 6. 20 7. 7 8. 18 9. 0 10. 18

Type 13: Input-Output Coding

1. cherry apple mango guava banana
2. banana cherry apple mango guava
3. guava banana cherry apple mango
4. mango guava banana cherry apple
5. apple mango guava banana cherry
6. 12 45 78 33 56
7. 12 45 33 78 56
8. 12 33 45 78 56
9. 12 33 45 56 78
10. 12 33 45 56 78 (fully sorted)

Type 14: Binary Coding

1. 00011-00001-10100 2. 10011-10101-01110 3. 00100-01111-00111 4. 01000-01001 5. 00001-00011-00101 6. 00010-01001-00111 7. 10010-10101-01110 8. 01101-00001-10000 9. 00110-01100-11001 10. 10111-01001-01110

Universal Step-by-Step Approach for Coding Decoding Reasoning

Use this exact process for every coding decoding reasoning question you attempt:

Step 1: Write the original word and its code side by side, letter by letter in aligned columns.

Step 2: Check for the simplest pattern first. Is the word just reversed? Check this in two seconds.

Step 3: Check for opposite coding. Add the position of original and coded letters. If the sum is always 27, it is the opposite coding.

Step 4: Check for fixed letter shift. Subtract the original letter’s position from the coded letter’s position. If the difference is the same for all letters, that is your shift.

Step 5: If no fixed shift, check for variable shift. Write the shift for each position. Look for a pattern like +1, +2, +3 or alternating values.

Step 6: Confirm the rule works for every single letter in the example. If even one letter breaks the rule, go back and look for a different pattern.

Step 7: Apply the confirmed rule to the target word carefully.

Step 8: Verify by reversing. Apply the opposite rule to your answer. If you get back the original word, your answer is correct.

Comparison of All Coding Decoding Reasoning Types

Tips to Score Full Marks in Coding Decoding Reasoning

• Memorize EJOTY. E=5, J=10, O=15, T=20, Y=25. This alone saves 5 to 10 seconds per question.
• Check the reverse first. Read the code backwards. Takes two seconds and eliminates one type instantly.
• Check opposite coding second. Add original and coded letter positions. If they add to 27, you are done.
• Always verify with all letters. One confirmation is not enough. Every letter must follow the rule before you apply it.
• For substitution questions, cross-match sentences. Never guess. Find the word that appears in two examples and match the repeated code.
• Watch for wrap-around. If a shift takes a letter beyond Z or before A, it wraps around. Z+1=A, A minus 1=Z.
• Eliminate wrong options in MCQs. Even before solving fully, check the first letter of your answer against the options. Eliminate non-matching choices and confirm from what remains.
• Practice 10 questions daily. Speed only comes from repeated exposure to patterns. Set a timer of 30 seconds per question and track your improvement weekly.

Also read – Smart Aptitude Test Preparation in 30 Days: Complete Guide to Crack Any Company Exam

Conclusion

Coding decoding reasoning is the only topic in competitive exam reasoning where every question has a guaranteed logical answer. There is no guessing, no ambiguity, and no exceptions. Once you identify the pattern correctly, the answer follows automatically. That makes it one of the most reliable scoring topics in any exam.

Start by mastering the three fastest types: reverse coding, opposite coding, and fixed letter shift. These three alone cover nearly 60 percent of all coding decoding reasoning questions in SSC and banking exams. Then move on to substitution coding and mixed coding. Practice 10 questions daily for two weeks and your speed will improve dramatically.

Coding decoding reasoning is not hard. It is just pattern recognition trained through practice. The more patterns you see, the faster your brain spots them in the exam hall.

FAQs

1. What is coding decoding reasoning?

Coding decoding reasoning is a logical reasoning topic where a word, number, or sentence is transformed into a coded form using a hidden rule. You have to identify the rule from a given example and apply the same rule to find the code or decode a new word. It appears in almost all competitive exams including SSC, banking, RRB, CAT, and placement tests.

2. How many types of coding decoding reasoning are there?

There are 14 main types of coding decoding reasoning: letter coding, opposite letter coding, reverse word coding, number coding, substitution coding, mixed shift coding, symbol or conditional coding, matrix coding, jumbled letter coding, place value coding, double shift coding, coded inequalities, input-output coding, and binary coding. Each type follows a distinct logical pattern.

3. What is the fastest way to solve coding decoding reasoning questions?

Write the original word and code side by side letter by letter. Check if the word is reversed in two seconds. Then check if positions add to 27 for opposite coding. Then check for a fixed shift. Always verify the rule on every letter before applying it to the target word.

4. What is the EJOTY trick in coding decoding reasoning?

EJOTY is a memory shortcut where E=5, J=10, O=15, T=20, Y=25. These five letters act as anchor points. To find any letter’s position quickly, find the nearest anchor and count forward or backward. For example R is 2 before T=20, so R=18. This saves several seconds per question.

5. Which exams have the most coding decoding reasoning questions?

SSC CGL, SSC CHSL, IBPS PO, SBI PO, RRB NTPC, and campus placement aptitude tests have the highest frequency of coding decoding reasoning questions, typically 3 to 5 questions per paper. Banking exams at the mains level often include more complex substitution and mixed coding questions.