Coding and decoding questions are a staple of competitive exams, testing your logical thinking, pattern recognition, and problem-solving abilities. These questions often appear in reasoning sections of exams like SSC, Banking, Railway, and many others. The key to cracking such questions lies in understanding the relationship between letters and numbers, patterns, or symbols.
In this article, we will explore various types of coding and decoding questions along with solutions, helping you understand how to tackle these problems efficiently.
Types of Coding and Decoding Questions
- Letter to Number Coding
- In these types of questions, letters of a word are assigned specific numerical values based on a certain logic.
- Example: If HOSPITAL is written as 32574618, how would POSTAL be written in that code?
- Solution: Each letter in HOSPITAL is mapped to a digit: H = 3, O = 2, S = 5, P = 7, I = 4, T = 6, A = 1, L = 8. For POSTAL, the corresponding digits are 7, 2, 5, 6, 1, 8. Hence, POSTAL = 725618.
- Mixed Letter and Number Coding
- These questions involve mixing letters and numbers to form a unique code for each word.
- Example: If HONESTY is written as 5132468 and POVERTY as 7192068, how is HORSE written?
- Solution: Map each letter to the corresponding digit: H = 5, O = 1, R = 0, S = 4, E = 2. Thus, HORSE = 51024.
- Positional Value Coding
- Here, the letters of the alphabet are converted to their positional values (A = 1, B = 2, …, Z = 26).
- Example: If JASMINE = 71, then ESTIMATE = ?
- Solution: The sum of the positional values of the letters in ESTIMATE (E = 5, S = 19, T = 20, I = 9, M = 13, A = 1, T = 20, E = 5) is 82.
- Letter Shifting
- These types of questions involve shifting each letter forward or backward in the alphabet.
- Example: If HONESTY is written as ABCXZDQ, how is TONY written?
- Solution: Each letter in HONESTY has been shifted to form ABCXZDQ: H → A, O → B, N → C, and so on. Applying the same rule to TONY, we get CQDC.
- Reverse Coding
- In reverse coding, the letters in a word are either reversed or their positions are altered in a fixed pattern.
- Example: If SISTER is written as RHRSDQ, how is UNCLE written?
- Solution: Using the same shifting pattern, we get UNCLE = TMBKD.
Coding and Decoding Practice Questions
Here are a series of questions to help you understand different types of coding and decoding.
1. If HOSPITAL is written as 32574618 in a certain code, how would POSTAL be written in that code ?
- (a) 752618
- (b) 725618
- (c) 725168
- (d) 725681
1. HOSPITAL = 32574618, POSTAL = ?
In the given code, each letter of the word “HOSPITAL” corresponds to a number as follows:
| H | O | S | P | I | T | A | L |
|---|---|---|---|---|---|---|---|
| 3 | 2 | 5 | 7 | 4 | 6 | 1 | 8 |
For POSTAL, match the letters with the corresponding digits:
- P = 7
- O = 2
- S = 5
- T = 6
- A = 1
- L = 8
Thus, POSTAL = 725618 (option b).
2. If HONESTY is written as 5132468 and POVERTY as 7192068, how is HORSE written in a certain code ?
- (a) 50124
- (b) 51042
- (c) 51024
- (d) 52014
HONESTY = 5132468, POVERTY = 7192068, HORSE = ?
The letters correspond to the following numbers:
| H | O | N | E | S | T | Y |
|---|---|---|---|---|---|---|
| 5 | 1 | 3 | 2 | 4 | 6 | 8 |
For HORSE:
- H = 5
- O = 1
- R = 0 (as found in POVERTY)
- S = 4
- E = 2
Thus, HORSE = 51024 (option c).
3. If ROSE is coded as 6821, CHAIR is 73456 and PREACH is coded as 961473, then what will be the code of SEARCH ?
- (a) 246173
- (b) 214673
- (c) 214763
- (d) 216473
ROSE = 6821, CHAIR = 73456, PREACH = 961473, SEARCH = ?
First, match the letters of SEARCH with the codes for ROSE, CHAIR, and PREACH:
| S | E | A | R | C | H |
|---|---|---|---|---|---|
| 6 | 8 | 1 | 2 | 4 | 3 |
Thus, SEARCH = 214673 (option b).
4. If ‘GIVE’ is coded as 5137 and ‘BAT’ is coded as 924, how is ‘GATE’ coded ?
- (a) 5427
- (b) 5724
- (c) 5247
- (d) 2547
GIVE = 5137, BAT = 924, GATE = ?
From the given codes, map each letter:
| G | I | V | E | B | A | T |
|---|---|---|---|---|---|---|
| 5 | 1 | 3 | 7 | 9 | 2 | 4 |
For GATE:
- G = 5
- A = 2
- T = 4
- E = 7
Thus, GATE = 5427 (option a).
5. If SEVEN is coded as 23136 and EIGHT as 34579, what will be the code for NINE ?
- (a) 6463
- (b) 6364
- (c) 6346
- (d) 6436
SEVEN = 23136, EIGHT = 34579, NINE = ?
From the code for SEVEN and EIGHT, map the numbers for NINE:
| N | I | N | E |
|---|---|---|---|
| 6 | 3 | 6 | 4 |
Thus, NINE = 6364 (option b).
6. If J = 10, JASMINE = 71, then ESTIMATE = ?
- (a) 71
- (b) 82
- (c) 92
- (d) 91
J = 10, JASMINE = 71, ESTIMATE = ?
Here, the sum of the positional values of letters (A = 1, B = 2, …, Z = 26) is used. Calculate the sum for ESTIMATE:
| E | S | T | I | M | A | T | E |
|---|---|---|---|---|---|---|---|
| 5 | 19 | 20 | 9 | 13 | 1 | 20 | 5 |
Sum = 5 + 19 + 20 + 9 + 13 + 1 + 20 + 5 = 82 (option b).
7. If A = 1, CAT = 24, then POLICE= ?
- (a) 57
- (b) 60
- (c) 62
- (d) 59
A = 1, CAT = 24, POLICE = ?
Calculate the positional values:
| P | O | L | I | C | E |
|---|---|---|---|---|---|
| 16 | 15 | 12 | 9 | 3 | 5 |
Sum = 16 + 15 + 12 + 9 + 3 + 5 = 60 (option b).
8. If A = 1; AND = 19 then BAT = ?
- (a) 22
- (b) 23
- (c) 21
- (d) 20
A = 1, AND = 19, BAT = ?
Using the same pattern:
| B | A | T |
|---|---|---|
| 2 | 1 | 20 |
Sum = 2 + 1 + 20 = 23 (option b).
9. If B = 2, MAT = 34, then JOGLEX= ?
- (a) 70
- (b) 71
- (c) 72
- (d) 73
B = 2, MAT = 34, JOGLEX = ?
Using positional values:
| J | O | G | L | E | X |
|---|---|---|---|---|---|
| 10 | 15 | 7 | 12 | 5 | 24 |
Sum = 10 + 15 + 7 + 12 + 5 + 24 = 73 (option d).
10. If HONESTY is written as ABCXZDQ, how can TONY be written in that code ?
- (a) DBCQ
- (b) QDCX
- (c) CBXZ
- (d) CQDC
HONESTY = ABCXZDQ, TONY = ?
By looking at letter shifts:
| H → A | O → B | N → C | E → X | S → Z | T → D | Y → Q |
|---|
For TONY:
- T → C
- O → Q
- N → D
- Y → C
Thus, TONY = CQDC (option d).
11. If LOSE is coded as 1357 and GAIN is coded as 2468, what do the figures 84615 stand for ?
- (a) NAILS
- (b) SNAIL
- (c) LANES
- (d) SLAIN
LOSE = 1357, GAIN = 2468, 84615 = ?
Match the digits to letters:
- 8 = S
- 4 = N
- 6 = A
- 1 = I
- 5 = L
Thus, 84615 = SNAIL (option b).
12. If ‘PENCIL’ is coded as ? @ , = ; 7 and ‘PAPER’ IS CODED AS ? 9 ?@ 5 how will you code ‘CLIP’ ?
- (a) @ 7 ‘ ?
- (b) @ ? ; ?
- (c) = 7 ? ;
- (d) = 7 ; ?
PENCIL = ? @ = ; 7, PAPER = ? 9 ?@ 5, CLIP = ?
Based on the given codes, for CLIP:
- C = =
- L = 7
- I = ;
- P = ?
Thus, CLIP = = 7 ; ? (option d).
13. If SPARK is coded as TQBSL, what will be the code for FLAME ?
- (a) GMBNF
- (b) GNBNF
- (c) GMCND
- (d) GMBMF
SPARK = TQBSL, FLAME = ?
By shifting each letter by one:
| F → G | L → M | A → B | M → N | E → F |
Thus, FLAME = GMBNF (option a).
14. In a certain code SISTER is written as RHRSDQ. How is UNCLE written in that code ?
- (a) TMBKD
- (b) TBMKD
- (c) TVBOD
- (d) TMKBD
SISTER = RHRSDQ, UNCLE = ?
Apply the same shifts:
| U → T | N → M | C → B | L → K | E → D |
Thus, UNCLE = TMBKD (option a).
15. If in a code language RUSTUM is written in INWANZ and RASTOGI is written is IXWVJK, how would RUSSIA be written in that code ?
- (a) INNWKJ
- (b) INNWKT
- (c) INWWKX
- (d) INNWNX
RUSTUM = INWANZ, RASTOGI = IXWVJK, RUSSIA = ?
Following the pattern:
| R → I | U → N | S → W | S → W | I → K | A → T |
Thus, RUSSIA = INNWKT (option b).
16. If BEAUTIFUL is written as CDOGHJKMN, how LEAF can be written in that code ?
- (a) NDOK
- (b) KNND
- (c) ODNK
- (d) DKON
BEAUTIFUL = CDOGHJKMN, LEAF = ?
Using the same coding scheme:
| L → O | E → D | A → N | F → K |
Thus, LEAF = ODNK (option c).
17. In a particular way the word STAG is coded as HGZT, HORN as SLIM. Using the same coding, how can NORTH be written ?
- (a) NLGMI
- (b) MLIGS
- (c) MGLIS
- (d) NLGIS
STAG = HGZT, HORN = SLIM, NORTH = ?
Following the same pattern:
| N → M | O → G | R → L | T → I | H → S |
Thus, NORTH = MGLIS (option c).
18. If MEKLF is coded as 91782 and LLLJK as 88867, then how can IGHED be coded ?
- (a) 97854
- (b) 64521
- (c) 53410
- (d) 75632
MEKLF = 91782, LLLJK = 88867, IGHED = ?
Based on the pattern:
- I = 9
- G = 7
- H = 8
- E = 5
- D = 4
Thus, IGHED = 97854 (option a).
19. If in a certain code, 95789 is written as EGKPT and 2436 is written as ALUR, then how will 24539 be written in that code ?
- (a) ALEUT
- (b) ALGTU
- (c) ALGUT
- (d) ALGRT
95789 = EGKPT, 2436 = ALUR, 24539 = ?
Using the same letter mappings:
- 2 = A
- 4 = L
- 5 = G
- 3 = U
- 9 = T
Thus, 24539 = ALGUT (option c).
20. If CAT is coded as 3120, what code number can be given to NAVIN ?
- (a) 14122914
- (b) 49274654
- (c) 73957614
- (d) None of these
CAT = 3120, NAVIN = ?
Use the pattern of positional values:
| N | A | V | I | N |
|---|---|---|---|---|
| 14 | 1 | 22 | 9 | 14 |
Thus, NAVIN = 14122914 (option a).
21. If in certain code ‘EDITION’ is written as 3891965, then how ‘TIDE’ will be written in that code ?
- (a) 3819
- (b) 1983
- (c) 1839
- (d) 1586
EDITION = 3891965, TIDE = ?
Using the same code system:
- T = 3
- I = 8
- D = 1
- E = 9
Thus, TIDE = 3819 (option a).
22. If UNIVERSITY is 1273948756, how can TRUSTY be written in that code ?
- (a) 542856
- (b) 531856
- (c) 541856
- (d) 541956
UNIVERSITY = 1273948756, TRUSTY = ?
Using the same code system:
- T = 5
- R = 4
- U = 1
- S = 8
- T = 5
- Y = 6
Thus, TRUSTY = 541856 (option c).
23. APPRECIATION is coded as 177832419465. How will you code PERCEPTION ?
- (a) 7382379465
- (b) 7392378465
- (c) 7292378465
- (d) 7383297465
APPRECIATION = 177832419465, PERCEPTION = ?
Using the same code system:
PERCEPTION = 7382379465 (option a).
24. If BANGALORE is written as 987685432, how is ELLORA written in the same code ?
- (a) 245538
- (b) 255438
- (c) 245348
- (d) 254538
BANGALORE = 987685432, ELLORA = ?
Using the same code system:
- E = 2
- L = 4
- L = 4
- O = 3
- R = 8
- A = 5
Thus, ELLORA = 245538 (option a).
25. If in a certain code, RAMAYANA is written as PYKYWLY, then how MAHABHARATA can be written in that code ?
- (a) NBIBCIBSBUB
- (b) LZGZAGZQZSZ
- (c) MCJCDJCTCVC
- (d) KYFYZFYPYRY
RAMAYANA = PYKYWLY, MAHABHARATA = ?
Following the same pattern:
| M → L | A → Z | H → G | A → Z | B → A | H → G | A → Z | R → Q | A → Z |
Thus, MAHABHARATA = LZGZAGZQZSZ (option b).
