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Coding and Decoding

43 questions

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Question 21Question →

In a certain code system, words are transformed according to the following rules:
1. Every vowel is replaced by its reverse alphabetical counterpart (where A↔ZA \leftrightarrow Z, E↔VE \leftrightarrow V, I↔RI \leftrightarrow R, O↔LO \leftrightarrow L, U↔FU \leftrightarrow F, such that the sum of the positional values of the original and transformed letter is 2727).
2. Every consonant located at an odd-numbered position in the word (1st, 3rd, 5th...) is replaced by the letter 33 steps ahead of it in the alphabetical series (+3+3).
3. Every consonant located at an even-numbered position in the word (2nd, 4th, 6th...) is replaced by the letter 22 steps behind it in the alphabetical series (−2-2).

If the word 'TRIANGLE' is coded as 'WPRZQEOV', which of the following represents the correct code for the word 'SOLUTION' in this language?

Show answer & explanation

Answer: VLOFWRLL

Answer

The correct code for the word 'SOLUTION' is 'VLOFWRLL'.
The correct code 'VLOFWRLL' is obtained by applying the specified rules systematically: 'S' (1st letter, consonant at odd position) becomes 'V' (+3+3); 'O' (2nd letter, vowel) becomes its reverse letter 'L' (27−15=1227-15=12); 'L' (3rd letter, consonant at odd position) becomes 'O' (+3+3); 'U' (4th letter, vowel) becomes its reverse letter 'F' (27−21=627-21=6); 'T' (5th letter, consonant at odd position) becomes 'W' (+3+3); 'I' (6th letter, vowel) becomes its reverse letter 'R' (27−9=1827-9=18); 'O' (7th letter, vowel) becomes its reverse letter 'L' (27−15=1227-15=12); and 'N' (8th letter, consonant at even position) becomes 'L' (−2-2).

Step-by-Step Solution

1
Analyze the rule verification on the example word 'TRIANGLE'
Position 1 (T, Consonant, Odd) →T+3=W\rightarrow T+3 = W; Position 2 (R, Consonant, Even) →R−2=P\rightarrow R-2 = P; Position 3 (I, Vowel) →27−9=18(R)\rightarrow 27-9 = 18 (R); Position 4 (A, Vowel) →27−1=26(Z)\rightarrow 27-1 = 26 (Z); Position 5 (N, Consonant, Odd) →N+3=Q\rightarrow N+3 = Q; Position 6 (G, Consonant, Even) →G−2=E\rightarrow G-2 = E; Position 7 (L, Consonant, Odd) →L+3=O\rightarrow L+3 = O; Position 8 (E, Vowel) →27−5=22(V)\rightarrow 27-5 = 22 (V). Output: 'WPRZQEOV'.
Confirms that the three-part rule set applies strictly by letter type and 1-indexed letter position.
2
Apply rules to the target word 'SOLUTION' letter by letter
1st letter 'S' (Odd pos, Consonant): S(19)+3=22(V)S (19) + 3 = 22 (V).
2nd letter 'O' (Vowel): Reverse of O(15)O (15) is 27−15=12(L)27 - 15 = 12 (L).
3rd letter 'L' (Odd pos, Consonant): L(12)+3=15(O)L (12) + 3 = 15 (O).
4th letter 'U' (Vowel): Reverse of U(21)U (21) is 27−21=6(F)27 - 21 = 6 (F).
5th letter 'T' (Odd pos, Consonant): T(20)+3=23(W)T (20) + 3 = 23 (W).
6th letter 'I' (Vowel): Reverse of I(9)I (9) is 27−9=18(R)27 - 9 = 18 (R).
7th letter 'O' (Vowel): Reverse of O(15)O (15) is 27−15=12(L)27 - 15 = 12 (L).
8th letter 'N' (Even pos, Consonant): N(14)−2=12(L)N (14) - 2 = 12 (L).
Evaluates each character in 'SOLUTION' according to its specific classification and position.
3
Combine transformed letters to get final coded string
'VLOFWRLL'
Concatenates individual output characters into the complete coded string.

Key Concept

Multi-rule positional letter shifting combined with reverse alphabetical indexing (27−n27 - n rule).
Question 22Question →

In a certain code system, words are transformed according to the following rules based on letter positions indexed 1,2,3,…,n1, 2, 3, \dots, n from left to right:
1. Letters at odd position indices (1,3,5,…1, 3, 5, \dots) are replaced by their reverse alphabetical counterparts (where A↔ZA \leftrightarrow Z, B↔YB \leftrightarrow Y, C↔XC \leftrightarrow X, etc.).
2. Letters at even position indices (2,4,6,…2, 4, 6, \dots) are replaced by the letter shifted forward in the English alphabet by a number of positions equal to their 1-based index (wrapping around from ZZ to AA if necessary).

Based on these rules, what is the correct code for the word 'JOURNEY'?

Show answer & explanation

Answer: QQFVMKB

Answer

QQFVMKB
The correct answer 'QQFVMKB' is obtained by applying the two positional rules step-by-step: at odd positions (1, 3, 5, 7), the reverse alphabetical positions (27−rank27 - \text{rank}) yield Q, F, M, and B respectively. At even positions (2, 4, 6), adding the letter's 1-based index to its rank gives Q (15 + 2 = 17), V (18 + 4 = 22), and K (5 + 6 = 11). Combining these yields 'QQFVMKB'.

Step-by-Step Solution

1
Identify the 1-based position index and standard alphabetical rank of each letter in 'JOURNEY'
J (pos 1, rank 10), O (pos 2, rank 15), U (pos 3, rank 21), R (pos 4, rank 18), N (pos 5, rank 14), E (pos 6, rank 5), Y (pos 7, rank 25).
Establishing letter positions and numerical ranks is required before applying positional transformation rules.
2
Apply reverse alphabetical substitution (27−rank27 - \text{rank}) to letters at odd positions (1, 3, 5, 7)
Position 1: 27−10=17→Q27 - 10 = 17 \rightarrow \text{Q}; Position 3: 27−21=6→F27 - 21 = 6 \rightarrow \text{F}; Position 5: 27−14=13→M27 - 14 = 13 \rightarrow \text{M}; Position 7: 27−25=2→B27 - 25 = 2 \rightarrow \text{B}.
Letters at odd position indices must be replaced by their reverse counterparts.
3
Apply forward shift by position index (rank+index)(\text{rank} + \text{index}) to letters at even positions (2, 4, 6)
Position 2: 15+2=17→Q15 + 2 = 17 \rightarrow \text{Q}; Position 4: 18+4=22→V18 + 4 = 22 \rightarrow \text{V}; Position 6: 5+6=11→K5 + 6 = 11 \rightarrow \text{K}.
Letters at even position indices are shifted forward by their respective 1-based index.
4
Combine the transformed letters in order from position 1 to 7
The encoded string is QQFVMKB.
Assembling the results from all letter positions yields the complete final code.

Key Concept

Positional Hybrid Coding (Reverse Indexing combined with Index-Based Forward Shift)
Estimated Time:1m 30s
Question 23Question →

In a certain code, if the word BLOCK is written as CMPDL, what is the code for the word TRAIN?

Show answer & explanation

Answer: USBJO; usbjo

Answer

USBJO
Each letter in the word is shifted forward by 1 position in the English alphabet (+1 rule). Applying this pattern to TRAIN yields USBJO.

Step-by-Step Solution

1
Analyze the rule used to transform BLOCK into CMPDL.
Each letter in BLOCK is replaced by its immediate next letter in the alphabetical order (+1 position shift): B → C, L → M, O → P, C → D, K → L.
Determining the pattern is necessary to encode new words.
2
Apply the same +1 shift rule to each letter of TRAIN.
T → U, R → S, A → B, I → J, N → O.
Applying the identified pattern consistently yields the correct encoded string.

Key Concept

Forward Letter Shifting (+1 Pattern)
Question 24Question →

In a certain code language, if the word "SMART" is written as "UOCTV", how is the word "LIGHT" written in that same code language?

Show answer & explanation

Answer: NKIJV

Answer

The word "LIGHT" is coded as "NKIJV".
Each letter of the original word is shifted forward by 2 positions in the English alphabet: L becomes N, I becomes K, G becomes I, H becomes J, and T becomes V. Combining these gives "NKIJV".

Step-by-Step Solution

1
Analyze the pattern from the given example pair "SMART" -> "UOCTV".
S (+2) -> U, M (+2) -> O, A (+2) -> C, R (+2) -> T, T (+2) -> V. The rule is adding 2 positions to each letter (+2 alphabetical shift).
Establishing the positional shift rule between corresponding letters.
2
Apply the identical +2 shift rule to each letter of the target word "LIGHT".
L (+2) -> N; I (+2) -> K; G (+2) -> I; H (+2) -> J; T (+2) -> V.
Executing the established shift logic to code the new word.
3
Combine the transformed letters.
The final coded word is "NKIJV".
Formulating the complete answer string.

Key Concept

Forward Positional Letter Coding
Question 25Question →

Match each original word in List-I with its correctly coded representation in List-II based on the logical transformation rules applied.

Click a left item, then click its matching right item

Items

PATIENT
HARVEST
DOMAINS
CLIMAX

Matches

Show answer & explanation

Answer

PATIENT matches SZWRQVW; HARVEST matches JZTEGHV; DOMAINS matches NPE1TOJ; CLIMAX matches HNEZZO.
Each word follows a specific multi-step transformation rule: PATIENT applies vowel replacement by reverse alphabet and +3+3 shift to consonants; HARVEST applies +2+2 shift to odd-positioned letters and reverse alphabet to even-positioned letters; DOMAINS reverses outer 3-letter blocks with a +1+1 shift while converting the central letter to its numeric position; CLIMAX applies consonant +2+2 and vowel −1-1 shifts within 3-letter halves before reversing each half.

Step-by-Step Solution

1
Analyze PATIENT transformation rule
Vowels (A,I,EA, I, E) use reverse positional mapping (27−position27 - \text{position}), yielding Z,R,VZ, R, V. Consonants (P,T,N,TP, T, N, T) shift +3+3, yielding S,W,Q,WS, W, Q, W. Combined: SZWRQVW.
Identify rule based on vowel vs. consonant classification.
2
Analyze HARVEST transformation rule
Odd indices (1,3,5,7→H,R,E,T1, 3, 5, 7 \rightarrow H, R, E, T) shift +2→J,T,G,V+2 \rightarrow J, T, G, V. Even indices (2,4,6→A,V,S2, 4, 6 \rightarrow A, V, S) take reverse alphabet values →Z,E,H\rightarrow Z, E, H. Combined: JZTEGHV.
Identify rule based on odd/even character indexing.
3
Analyze DOMAINS transformation rule
First half 'DOM' →\rightarrow reversed 'MOD' →+1\rightarrow +1 shift 'NPE'. Central letter 'A' →\rightarrow numerical rank 11. Second half 'INS' →\rightarrow reversed 'SNI' →+1\rightarrow +1 shift 'TOJ'. Combined: NPE1TOJ.
Identify structural split, segment reversal, positional shift, and numerical conversion.
4
Analyze CLIMAX transformation rule
First half 'CLI': consonants +2+2, vowel −1→-1 \rightarrow 'ENH', reversed →\rightarrow 'HNE'. Second half 'MAX': consonants +2+2, vowel −1→-1 \rightarrow 'OZZ', reversed →\rightarrow 'ZZO'. Combined: HNEZZO.
Identify sub-string segmentation, character-type conditional shifts, and section inversion.

Key Concept

Multi-rule complex coding-decoding involving conditional letter shifts, positional indices, reverse alphabetical mapping, and string segmentation.
Question 26Question →

In a certain code language, the word BEACON is written as DGCEQP. How is the word MONKEY written in that same code language?

Show answer & explanation

Answer: OQPMGA

Answer

OQPMGA
The pattern follows a constant shift of +2 positions forward in alphabetical order for every letter: B→D, E→G, A→C, C→E, O→Q, N→P. Applying the same rule to MONKEY gives M→O, O→Q, N→P, K→M, E→G, and Y→A (wrapping around after Z), resulting in OQPMGA.

Step-by-Step Solution

1
Analyze the rule given by the pattern BEACON to DGCEQP.
B (+2) = D, E (+2) = G, A (+2) = C, C (+2) = E, O (+2) = Q, N (+2) = P. The pattern is a uniform forward shift of +2 for every letter.
Determining the transformation rule from the given pair is required to decode the target word.
2
Apply the identified +2 forward shift to each letter of MONKEY.
M (+2) = O, O (+2) = Q, N (+2) = P, K (+2) = M, E (+2) = G, Y (+2) = A.
Applying the exact pattern step-by-step gives the coded output.

Key Concept

Forward Letter Shift Coding
Estimated Time:45s
Question 27Question →

In a certain code language, the word CENTRAL is written as AYKEGCM. Based on the same underlying transformation rule, how will the word PRUDENT be written in that code language?

Show answer & explanation

Answer: IGIUYKE

Answer

IGIUYKE
The code is formed by replacing each letter with its reverse alphabetical position value (where A=26, B=25, ..., Z=1), then adding 3 if the value is even or subtracting 2 if it is odd, and finally mapping the resulting number back to the standard 1-26 forward alphabetical index. Applying this process to PRUDENT yields IGIUYKE.

Step-by-Step Solution

1
Analyze the coding rule using the example word CENTRAL
Determine forward and reverse alphabetical positions for each letter: C(3→24), E(5→22), N(14→13), T(20→7), R(18→9), A(1→26), L(12→15).
Identify the positional value system being transformed.
2
Identify the conditional transformation rule applied to the reverse positional values
If reverse position is EVEN, add 3; if ODD, subtract 2. Convert back to standard forward letter: C(24+3=27≡1→A), E(22+3=25→Y), N(13-2=11→K), T(7-2=5→E), R(9-2=7→G), A(26+3=29≡3→C), L(15-2=13→M). This matches AYKEGCM.
Establish the precise pattern rules for decoding target words.
3
Apply the rule to the target word PRUDENT
P(16→11 odd: 11-2=9→I), R(18→9 odd: 9-2=7→G), U(21→6 even: 6+3=9→I), D(4→23 odd: 23-2=21→U), E(5→22 even: 22+3=25→Y), N(14→13 odd: 13-2=11→K), T(20→7 odd: 7-2=5→E).
Generate the coded string systematically letter by letter.

Key Concept

Reverse Alphabetical Indexing with Conditional Numerical Shifting
Estimated Time:2m 0s
Question 28Question →

Match each word transformation in List-I with its correct letter-shifting rule in List-II.

Click a left item, then click its matching right item

Items

PEN → QFO
PEN → RGP
PEN → SHQ
PEN → TIR

Matches

Show answer & explanation

Answer

PEN → QFO matches +1 shift; PEN → RGP matches +2 shift; PEN → SHQ matches +3 shift; PEN → TIR matches +4 shift.
Each transformation applies a uniform forward alphabetical shift across all letters: +1 for QFO, +2 for RGP, +3 for SHQ, and +4 for TIR.

Step-by-Step Solution

1
Analyze PEN → QFO
P to Q (+1), E to F (+1), N to O (+1). Rule is +1 shift.
Identify the positional distance between corresponding alphabetical letters.
2
Analyze PEN → RGP
P to R (+2), E to G (+2), N to P (+2). Rule is +2 shift.
Identify the positional distance between corresponding alphabetical letters.
3
Analyze PEN → SHQ
P to S (+3), E to H (+3), N to Q (+3). Rule is +3 shift.
Identify the positional distance between corresponding alphabetical letters.
4
Analyze PEN → TIR
P to T (+4), E to I (+4), N to R (+4). Rule is +4 shift.
Identify the positional distance between corresponding alphabetical letters.

Key Concept

Constant Forward Letter Shifting
Question 29Question →

In a certain code language, if the word "DESK" is written as "EFTL", how is the word "LAMP" written in that code language?

Show answer & explanation

Answer: MBNQ

Answer

MBNQ
Each letter in the original word is replaced by its immediate next letter in the English alphabet (+1 positional shift). Shifting the letters of LAMP forward by 1 position gives L → M, A → B, M → N, and P → Q, resulting in MBNQ.

Step-by-Step Solution

1
Analyze the rule used to code DESK into EFTL.
D → E (+1), E → F (+1), S → T (+1), K → L (+1). The pattern is a +1 forward shift for each letter.
Establishing the exact letter transformation rule from the given example.
2
Apply the identified +1 forward shift rule to the target word LAMP.
L → M (+1), A → B (+1), M → N (+1), P → Q (+1).
Executing the rule consistently across all positions in the word LAMP.

Key Concept

Letter-Shift Coding Rule (+1 Forward Shift)
Question 30Question →

In a certain code language, the word DISRUPT is written as GSFUHLW. Based on the same logical transformation rule, how is the word PATIENT written in that code language?

Show answer & explanation

Answer: GQVLGDK

Answer

The word PATIENT is coded as GQVLGDK.
The correct answer GQVLGDK is formed by taking the word PATIENT, replacing letters at odd positions with their opposite alphabetical letters (27−alphabet position27 - \text{alphabet position}), advancing letters at even positions by +3+3, and reversing the overall string sequence.

Step-by-Step Solution

1
Analyze the letter transformations in the example word DISRUPT (7 letters).
Letters at odd positions (1st, 3rd, 5th, 7th) are replaced by their reverse alphabetical counterparts (A↔Z,B↔YA \leftrightarrow Z, B \leftrightarrow Y, calculated as 27−position27 - \text{position}). Letters at even positions (2nd, 4th, 6th) are shifted forward by +3+3 steps in the alphabet.
Identifying the positional parity rules from the sample word.
2
Transform each letter of DISRUPT individually.
D(1, odd) →\rightarrow W (27-4=23); I(2, even) →\rightarrow L (9+3=12); S(3, odd) →\rightarrow H (27-19=8); R(4, even) →\rightarrow U (18+3=21); U(5, odd) →\rightarrow F (27-21=6); P(6, even) →\rightarrow S (16+3=19); T(7, odd) →\rightarrow G (27-20=7). Intermediate string: WLHUFSG.
Deriving the intermediate string prior to reversal.
3
Reverse the order of the intermediate string WLHUFSG.
Reversing WLHUFSG yields GSFUHLW, matching the code given in the problem stem.
Confirming the complete multi-step transformation rule.
4
Apply the verified rule to the target word PATIENT.
P(1, odd) →\rightarrow K (27-16=11); A(2, even) →\rightarrow D (1+3=4); T(3, odd) →\rightarrow G (27-20=7); I(4, even) →\rightarrow L (9+3=12); E(5, odd) →\rightarrow V (27-5=22); N(6, even) →\rightarrow Q (14+3=17); T(7, odd) →\rightarrow G (27-20=7). Intermediate string: KDGLVQG.
Computing transformed letters for all positions in PATIENT.
5
Reverse the intermediate string KDGLVQG.
Reversing KDGLVQG produces the final code GQVLGDK.
Completing the final operation of the coding rule.

Key Concept

Positional parity-based letter transformation combined with reverse alphabetical indexing and string reversal.
Estimated Time:2m 0s
Question 31Question →

In a specific coding system, the word PARDON is written as MRWUZS. Following the exact same logical transformation rule, what is the code for the word POSTURE?

Show answer & explanation

Answer: HIXGVLS; hixgvls

Answer

HIXGVLS
The code is determined by applying two transformation rules based on letter positions followed by a string reversal. Letters at odd positions (1st, 3rd, 5th, 7th) undergo a +3+3 forward alphabetical shift, while letters at even positions (2nd, 4th, 6th) are replaced by their reverse alphabetical partner (27−alphabetical position27 - \text{alphabetical position}). For the word POSTURE, this yields the intermediate string SLVGXIH. Reversing this intermediate string produces the final code HIXGVLS.

Step-by-Step Solution

1
Analyze the position-based transformation rules for each letter of the original word.
Letters at odd positions (1st, 3rd, 5th...) are shifted forward by +3+3 positions in the English alphabetical series. Letters at even positions (2nd, 4th, 6th...) are replaced by their reverse alphabetical partner (where position index sum equals 2727).
For PARDON: P (1st, odd) →\rightarrow S; A (2nd, even) →\rightarrow Z; R (3rd, odd) →\rightarrow U; D (4th, even) →\rightarrow W; O (5th, odd) →\rightarrow R; N (6th, even) →\rightarrow M. The intermediate string is SZUWRM.
2
Identify the final structural modification step.
The intermediate letter sequence is reversed from right to left.
Reversing SZUWRM character-by-character gives MRWUZS.
3
Apply the odd/even position rules to the target word POSTURE.
P (1st, odd) +3→+3 \rightarrow S; O (2nd, even) 27−15=12→27-15=12 \rightarrow L; S (3rd, odd) +3→+3 \rightarrow V; T (4th, even) 27−20=7→27-20=7 \rightarrow G; U (5th, odd) +3→+3 \rightarrow X; R (6th, even) 27−18=9→27-18=9 \rightarrow I; E (7th, odd) +3→+3 \rightarrow H. Intermediate string is SLVGXIH.
Odd indices shift by +3+3, and even indices transform to reverse alphabetical complements.
4
Reverse the intermediate sequence to obtain the final coded answer.
HIXGVLS
Reversing SLVGXIH gives HIXGVLS.

Key Concept

Position-dependent shift combined with reverse alphabetical indexing and string reversal
Estimated Time:2m 0s
Question 32Question →

During an archaeological excavation, researchers found a set of tablets with inscriptions. By comparing contextual texts, they established the following phrase translations:

'ancient hidden temple' is coded as 'zola mizu kanto'
'hidden gold treasure' is coded as 'mizu pelta vosh'
'ancient stone treasure' is coded as 'kanto nubo vosh'
'stone temple pathway' is coded as 'nubo zola rima'

Based on this information, match each English word with its corresponding ancient code.

Click a left item, then click its matching right item

Items

ancient
hidden
treasure
temple

Matches

Show answer & explanation

Answer

The correct matching is: 'ancient' matches with 'kanto', 'hidden' matches with 'mizu', 'treasure' matches with 'vosh', and 'temple' matches with 'zola'.
By systematically comparing pairs of phrases that share exactly one common English word, we can isolate the corresponding common code word regardless of its position in the sentence. This logical intersection process reveals that 'ancient' = 'kanto', 'hidden' = 'mizu', 'treasure' = 'vosh', and 'temple' = 'zola'.

Step-by-Step Solution

1
Compare the first phrase ('ancient hidden temple') and the third phrase ('ancient stone treasure').
The common English word is 'ancient' and the common code is 'kanto'.
Finding the intersection of words and codes between two phrases isolates the translation for the shared word.
2
Compare the first phrase ('ancient hidden temple') and the second phrase ('hidden gold treasure').
The common English word is 'hidden' and the common code is 'mizu'.
Applying the same intersection method identifies the code for the next target word.
3
Compare the second phrase ('hidden gold treasure') and the third phrase ('ancient stone treasure').
The common English word is 'treasure' and the common code is 'vosh'.
This confirms the translation for 'treasure' by isolating it across two different contexts.
4
Compare the first phrase ('ancient hidden temple') and the fourth phrase ('stone temple pathway').
The common English word is 'temple' and the common code is 'zola'.
This completes the required mapping for all four target words.

Key Concept

Phrase Substitution and Matrix Decoding
Question 33Question →

An automated transit gate authenticates employee badges by generating a daily encrypted code based on the employee's assigned sector. When an employee's sector is WINTER, the authentication code generated is ZKOWGS.

Applying the identical logical sequence, what authentication code will be generated if an employee's sector is SPRING?

Show answer & explanation

Answer: VRSLPH; vrslph

Answer

VRSLPH
The system encrypts words by applying a repeating forward alphabetical shift of +3, +2, and +1 to consecutive letters. Applying this sequence to SPRING (S+3, P+2, R+1, I+3, N+2, G+1) results in VRSLPH.

Step-by-Step Solution

1
Determine the numerical alphabetical positions of the letters in the reference word 'WINTER' and its code 'ZKOWGS'.
W=23, I=9, N=14, T=20, E=5, R=18. Z=26, K=11, O=15, W=23, G=7, S=19.
Converting letters to their numerical positions allows us to mathematically determine the shift pattern.
2
Calculate the difference between the numerical positions of corresponding letters.
26-23 = +3; 11-9 = +2; 15-14 = +1; 23-20 = +3; 7-5 = +2; 19-18 = +1.
This reveals the underlying logical pattern: a repeating sequence of +3, +2, +1 shifts.
3
Identify the numerical positions of the letters in the target word 'SPRING'.
S=19, P=16, R=18, I=9, N=14, G=7.
These are the base values to which the shift pattern must be applied.
4
Apply the +3, +2, +1 repeating shift sequence to the numerical positions of 'SPRING' and convert back to letters.
19+3=22(V); 16+2=18(R); 18+1=19(S); 9+3=12(L); 14+2=16(P); 7+1=8(H). The result is VRSLPH.
Applying the exact same logical transformation rule yields the final encrypted code.

Key Concept

Identifying and applying sequential mathematical shifts to alphabetical characters.
Question 34Question →

In a covert military operation, communication officers use a specific cryptographic algorithm to secure tactical locations. If the location BRIDGE is encoded as VTWRIY, which of the following represents the code for the location HARBOR?

Show answer & explanation

Answer: ILYIZS

Answer

The cryptographic code for HARBOR is ILYIZS.
The correct answer accurately applies both steps of the established encryption algorithm: first replacing each letter in HARBOR with its alphabetical opposite (yielding SZIYLI), and then completely reversing the resulting string to arrive at ILYIZS.

Step-by-Step Solution

1
Determine the transformation rule applied to the letters of the given word BRIDGE.
Each letter is replaced by its opposite in the alphabet (Reverse Alphabetical Index, where A=Z, B=Y, etc.). B(2) becomes Y(25), R(18) becomes I(9), I(9) becomes R(18), D(4) becomes W(23), G(7) becomes T(20), and E(5) becomes V(22). The resulting sequence is YIRWTV.
Establishing the initial letter substitution mapping is the first step in decoding the algorithm.
2
Compare the sequence of opposite letters to the final encrypted code.
The intermediate sequence YIRWTV is reversed to become VTWRIY, matching the given code.
Identifying any secondary transformations (like string reversal) ensures the complete algorithm is understood.
3
Apply the reverse alphabetical index to the target word HARBOR.
H(8) becomes S(19), A(1) becomes Z(26), R(18) becomes I(9), B(2) becomes Y(25), O(15) becomes L(12), and R(18) becomes I(9). The intermediate sequence is SZIYLI.
This executes the first half of the decoded algorithmic rule on the required word.
4
Apply the string reversal to the intermediate sequence.
Reversing SZIYLI results in ILYIZS.
This executes the final step of the algorithm to obtain the exact encrypted code.

Key Concept

Reverse Alphabetical Indexing and String Reversal
Question 35Question →

A cryptographer is analyzing intercepted transmissions and has successfully aligned three coded messages with their English translations. Note that the order of words in the coded messages does not necessarily correspond to the order of words in the English translations.

1. 'alpha delta echo' translates to 'secure the perimeter'
2. 'echo bravo charlie' translates to 'the main target'
3. 'alpha charlie foxtrot' translates to 'secure main exit'

Based on these translations, match each English word with its corresponding coded term.

Click a left item, then click its matching right item

Items

secure
the
perimeter
main

Matches

Show answer & explanation

Answer

The correct matches are: 'secure' corresponds to 'alpha', 'the' corresponds to 'echo', 'perimeter' corresponds to 'delta', and 'main' corresponds to 'charlie'.
By cross-referencing phrases that share common words, we isolate specific codes. 'secure' is shared by phrases 1 and 3 (yielding 'alpha'). 'the' is shared by phrases 1 and 2 (yielding 'echo'). 'main' is shared by phrases 2 and 3 (yielding 'charlie'). Consequently, 'perimeter' in phrase 1 must be the remaining code 'delta'.

Step-by-Step Solution

1
Analyze the first and second phrases for common words and codes.
Common English word: 'the'. Common coded term: 'echo'.
Finding elements common to two sets is the primary deductive method for deciphering substitution matrices.
2
Analyze the first and third phrases for common words and codes.
Common English word: 'secure'. Common coded term: 'alpha'.
This establishes another direct translation pair by isolating shared terms.
3
Use the known translations to deduce the remaining words in the first phrase.
Since 'secure' is 'alpha' and 'the' is 'echo', the final word 'perimeter' must map to the remaining code 'delta'.
Process of elimination within a fully mapped phrase confirms the final mapping.
4
Analyze the second and third phrases for common words and codes.
Common English word: 'main'. Common coded term: 'charlie'.
This confirms the translation for 'main' and completes the required matching.

Key Concept

Sentence Substitution Matrices
Estimated Time:1m 0s
Question 36Question →

During a cybersecurity drill, passwords are obfuscated using a specific two-step alphabetic logic. If the system transforms the access word TABLE into HAZPW, what will the access word CHAIR be transformed into under the same logic?

Show answer & explanation

Answer: YTASJ

Answer

The correct transformation for the word CHAIR is YTASJ.
The encryption logic applies a reverse alphabetical index to each letter (where A=Z, B=Y, etc.) and then shifts that result forward by one letter (+1). Applying this to CHAIR gives the intermediate letters XSZRI, which then shift +1 to become YTASJ.

Step-by-Step Solution

1
Analyze the transformation from TABLE to HAZPW to identify the first logical step.
The reverse alphabetical equivalents for T-A-B-L-E are G-Z-Y-O-V.
Finding the foundational pattern requires testing common cryptographic shifts, starting with opposite letters.
2
Determine the second logical step by comparing the intermediate reversed letters to the final code.
Shifting G-Z-Y-O-V forward by one letter (+1) in the alphabet results in H-A-Z-P-W.
This confirms the two-step logic: reverse the letter, then shift +1.
3
Apply the first step (reverse alphabet) to the target word CHAIR.
The reverse alphabetical equivalents for C-H-A-I-R are X-S-Z-R-I.
To begin encrypting the new access word according to the established rule.
4
Apply the second step (+1 shift) to the intermediate result.
Shifting X-S-Z-R-I forward by one letter (+1) results in Y-T-A-S-J.
To complete the obfuscation logic and determine the final coded sequence.

Key Concept

Reverse Alphabetical Indexing and Positional Shifting
Question 37Question →

A metropolitan transport network assigns an identification string to each station name using a consistent alphabetic transformation logic. Under this system, the station named NORTH is encoded as OQUXM, and the station named SOUTH is encoded as TQXXM.

What will be the encoded identification string for the station named CENTRAL?

Show answer & explanation

Answer: DGQXWGS; dgqxwgs

Answer

DGQXWGS
The coding logic applies an increasing forward shift to the English alphabet based on the letter's position in the word (1st letter +1, 2nd letter +2, 3rd letter +3, etc.). Applying this sequence to CENTRAL (C+1, E+2, N+3, T+4, R+5, A+6, L+7) yields DGQXWGS.

Step-by-Step Solution

1
Analyze the transformation pattern from the first example, NORTH to OQUXM.
N(+1) = O; O(+2) = Q; R(+3) = U; T(+4) = X; H(+5) = M.
To identify the underlying coding rule, which involves an increasing positional shift.
2
Verify the identified pattern using the second example, SOUTH to TQXXM.
S(+1) = T; O(+2) = Q; U(+3) = X; T(+4) = X; H(+5) = M.
To confirm that the logic applies consistently across different inputs.
3
Calculate the shifted letters for the target word CENTRAL by applying the verified pattern.
C(+1)=D, E(+2)=G, N(+3)=Q, T(+4)=X, R(+5)=W, A(+6)=G, L(+7)=S.
To determine the final encoded string according to the established algorithm.

Key Concept

Positional Alphabet Shifting
Question 38Question →

A digital library archiving system generates tags for its collections using a specific alphabetic transformation logic. In this system, the word INDEX is coded as GQGCA, and the word BOOK is coded as EMMN.

Using the exact same logic, what is the exact code for the word SHELF?

Show answer & explanation

Answer: VKCOI; vkcoi

Answer

VKCOI
The established coding rule categorizes letters into consonants and vowels. Consonants are shifted forward by 3 alphabetical positions in a circular manner, while vowels are shifted backward by 2 positions. Applying this specific rule to the word SHELF: S (consonant + 3) = V, H (consonant + 3) = K, E (vowel - 2) = C, L (consonant + 3) = O, and F (consonant + 3) = I. This produces the final correct code VKCOI.

Step-by-Step Solution

1
Analyze the first example 'INDEX' to identify the alphabetical shift pattern for each letter.
I (-2) = G, N (+3) = Q, D (+3) = G, E (-2) = C, X (+3) = A.
Determining the numerical alphabetical shift for each individual letter is the foundational step in decoding the logic.
2
Analyze the second example 'BOOK' to verify the logic and rule out position-based shifting.
B (+3) = E, O (-2) = M, O (-2) = M, K (+3) = N.
A second example confirms whether the shift depends on the letter's position in the word or its phonetic classification (vowel vs. consonant).
3
Deduce the universal coding rule from the confirmed shift patterns.
Consonants are shifted forward by 3 positions (+3), and vowels are shifted backward by 2 positions (-2).
A consistent, unified rule must be fully established before attempting to encode the target word.
4
Apply the deduced rule to the target word 'SHELF'.
S (consonant) + 3 = V, H (consonant) + 3 = K, E (vowel) - 2 = C, L (consonant) + 3 = O, F (consonant) + 3 = I.
Executing the exact transformation on the target string yields the final requested code.

Key Concept

Alphabetic transformation using conditional logic based on vowel and consonant classification.
Estimated Time:1m 30s
Question 39Question →

In a museum's digital archiving system, historical artifacts are tagged using a specific alphabetical transformation pattern. For example, the tag for SEAL is generated as TDBK, and the tag for IRON is generated as JQPM. Based on this established coding logic, match the following artifact materials with their correct encoded tags.

Click a left item, then click its matching right item

Items

CLAY
SILK
WOOD
JADE

Matches

Show answer & explanation

Answer

The correct matches are: CLAY with DKBX, SILK with THMJ, WOOD with XNPC, and JADE with KZED.
By analyzing the given examples, the coding logic follows a strict alternating sequence of shifting the first letter forward by one position (+1), the second letter backward by one position (-1), the third forward by one (+1), and the fourth backward by one (-1) according to the standard English alphabet.

Step-by-Step Solution

1
Analyze the first example code (SEAL to TDBK) to find the position shift logic.
S to T is +1; E to D is -1; A to B is +1; L to K is -1.
Identifying the letter-by-letter transformation rule is the fundamental first step in decoding the pattern.
2
Verify the hypothesized rule with the second example (IRON to JQPM).
I(+1)=J, R(-1)=Q, O(+1)=P, N(-1)=M. The pattern is consistently an alternating +1 and -1 shift.
Confirming the rule with a second example ensures the deduced logic is universally applied and not coincidental.
3
Apply the alternating +1, -1, +1, -1 rule to each of the given artifact materials.
CLAY translates to DKBX. SILK translates to THMJ. WOOD translates to XNPC. JADE translates to KZED.
This generates the final encoded tags to pair with the original given items.

Key Concept

Alternating Alphabetical Position Shifts
Question 40Question →

A global supply chain software tracks cargo shipments by encrypting destination city names to ensure data privacy. In this system, the destination "LONDON" is coded as "OLMFQP" and "BERLIN" is coded as "YVINKP". Based on this coding logic, how will the destination "MUMBAI" be coded in this tracking system?

Show answer & explanation

Answer: NFNDCK

Answer

NFNDCK
The coding logic splits the word into two equal halves. The letters in the first half are replaced by their reverse alphabetical counterparts (i.e., A=Z, B=Y, or position 27 - n). The letters in the second half are shifted forward by 2 positions in the alphabet. For 'MUMBAI', the first half 'MUM' becomes 'NFN' through reverse indexing, and the second half 'BAI' becomes 'DCK' through a +2 shift. Combining these yields 'NFNDCK'.

Step-by-Step Solution

1
Analyze the first example "LONDON" -> "OLMFQP" by comparing the alphabetical positions of the letters.
The word is split into two equal halves: "LON" and "DON". 'L' becomes 'O', 'O' becomes 'L', 'N' becomes 'M'. 'D' becomes 'F', 'O' becomes 'Q', 'N' becomes 'P'.
To identify the underlying mathematical transformation rules applied to the letters.
2
Determine the specific logical rules for each half of the word.
For the first half ("LON" -> "OLM"), each letter is replaced by its reverse alphabetical counterpart (e.g., L is the 12th letter from the start, O is 12th from the end; mathematically, 27 - 12 = 15). For the second half ("DON" -> "FQP"), each letter is shifted forward by 2 positions (+2).
To establish a concrete, two-part rule that can be verified and applied.
3
Verify the extracted rules using the second example "BERLIN" -> "YVINKP".
Split into "BER" and "LIN". The reverse alphabetical index of B, E, R gives Y, V, I. Shifting L, I, N forward by 2 gives N, K, P. The rule holds perfectly.
To ensure the pattern is consistent and correct before applying it to the target word.
4
Apply the verified rules to the target word "MUMBAI".
Split into "MUM" and "BAI". Reverse index for MUM: M(13) → N(14), U(21) → F(6), M(13) → N(14). Forward +2 shift for BAI: B(2) → D(4), A(1) → C(3), I(9) → K(11). Combining these halves gives "NFNDCK".
To calculate the final encrypted code based on the established logic.

Key Concept

Identifying split-pattern coding sequences utilizing reverse alphabetical indexing and positional shifts.
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