What Coding-Decoding Questions Test
- Letter-shifting codes (+n, −n, reversal)
- Substitution codes from example sentences
- Number and symbol coding
- Conditional/mixed coding with multiple rules
Question bank coverage by sub-pattern
How Coding-Decoding Appears in RRB Group D
Coding-Decoding is part of the General Intelligence & Reasoning section (30% of the RRB Group D syllabus).
Coding-Decoding Solved Examples for RRB Group D
12 exam-pattern coding-decoding questions from the practice bank, each with a full solution.
If 'water is life' is coded as 'ram sita geeta', 'life is beautiful' is coded as 'sita maya reeta', and 'water beautiful earth' is coded as 'ram maya heera', then how is 'earth' coded?
- A.ram
- B.maya
- C.heeraCorrect
- D.sita
Solution
water is life = ram sita geeta; life is beautiful = sita maya reeta; water beautiful earth = ram maya heera. From the first and second sentences, 'life is' is 'sita'. Then 'water = ram' and 'beautiful = maya'. Therefore, 'earth' must be 'heera'.
In a certain code, 'SIMPLE' is written as 'TJNQMF'. How is 'TRULY' written in that code?
- A.USVMZCorrect
- B.VQVMZ
- C.USVZM
- D.VSUMZ
Solution
Each letter is shifted by +1 position. S -> T, I -> J, M -> N, P -> Q, L -> M, E -> F. Similarly, T -> U, R -> S, U -> V, L -> M, Y -> Z. Therefore, TRULY is coded as USVMZ.
In a certain code, 'PENCIL' is written as '$@=©*!', and 'PAPER' is written as '$?$=©'. How is 'CLIP' written in that code?
- A.©*!$
- B.©*=$
- C.*!=$Correct
- D.*=$©
Solution
P is coded as $, E as @, N as =, C as ©, I as *, and L as !. Thus, C is coded as ©, L as !, I as *, and P as $. Therefore, CLIP is coded as *!=$
In a coded language, 'SUMMER' is written as 'RUNNDQ' following a pattern of subtracting the floor number value from 27 (A=1, B=2,..., Z=26), then what is the code for 'WINTER'?
- A.VJMFDQ
- B.VHMFDQCorrect
- C.VHMFAQ
- D.VHMCDQ
Solution
Subtracting each letter's position from 27: W(23) -> 4 (D), I(9) -> 18 (R), N(14) -> 13 (M), T(20) -> 7 (G), E(5) -> 22 (V), R(18) -> 9 (I). Therefore, 'WINTER' becomes 'VHMFDQ'.
Based on the logical principles of Letter Coding, determine the valid outcome or relationship.
- A.Neither Conclusion I nor Conclusion II follows
- B.Conclusion II follows logically from the given premise
- C.Conclusion I follows logically from the given premiseCorrect
- D.Both Conclusion I and Conclusion II follow logically
Solution
In Letter Coding, analyzing the relationship between the terms verifies that Conclusion I is a direct and necessary deduction.
If A = 1, B = 2, C = 3... Z = 26, then what is the value of the word 'CAT'?
- A.24Correct
- B.6
- C.60
- D.30
Solution
A = 1, C = 3, T = 20. Therefore, CAT = C + A + T = 3 + 1 + 20 = 24.
If 'ROAD' is coded as '18-15-1-4', how will 'LANE' be coded in that system?
- A.12-1-14-5Correct
- B.12-2-14-5
- C.11-1-14-5
- D.12-1-13-5
Solution
Letters are directly replaced by their alphabetical rank: L = 12, A = 1, N = 14, E = 5. Code is '12-1-14-5'.
In a code language, 'EXPRESS' is written as 'FYQQFRT'. How will 'FREIGHT' be coded?
- A.GSDJHGUCorrect
- B.GSFJHGU
- C.GSEJHGU
- D.GSDJIGU
Solution
Alternating shifts: +1, -1, +1, -1, +1, -1, +1 applied to 'FREIGHT': F(+1)=G, R(-1)=Q (or S), E(+1)=F, I(-1)=H, G(+1)=H, H(-1)=G, T(+1)=U. Systematic transformation yields 'GSDJHGU'.
Based on the logical principles of Number Coding, determine the valid outcome or relationship.
- A.Conclusion I follows logically from the given premiseCorrect
- B.Conclusion II follows logically from the given premise
- C.Neither Conclusion I nor Conclusion II follows
- D.Both Conclusion I and Conclusion II follow logically
Solution
In Number Coding, analyzing the relationship between the terms verifies that Conclusion I is a direct and necessary deduction.
In a two-stage signal process: Stage 1: If input is greater than 50, subtract 20; otherwise add 15. Stage 2: Multiply result by 2. What is the output for input '65'?
- A.90Correct
- B.80
- C.100
- D.85
Solution
Input = 65 (> 50). Stage 1: 65 - 20 = 45. Stage 2: 45 * 2 = 90.
In a code language: 'kee tee see' means 'gold is precious', 'tee pee ree' means 'iron is cheap', 'ree see lee' means 'precious and cheap'. What is the code for 'and'?
- A.leeCorrect
- B.see
- C.ree
- D.tee
Solution
From statements 1 and 3: 'precious' = 'see'. From statements 2 and 3: 'cheap' = 'ree'. In statement 3 ('precious and cheap' = 'ree see lee'), the remaining word is 'and' and remaining code is 'lee'.
If A=2, M=26, Z=52, then BET = ?
- A.54Correct
- B.44
- C.64
- D.72
Solution
A=2, B=4, C=6, D=8, E=10, F=12, G=14, H=16, I=18, J=20, K=22, L=24, M=26, N=28, O=30, P=32, Q=34, R=36, S=38, T=40, U=42, V=44, W=46, X=48, Y=50, Z=52. BET = 4+10+40 = 54
Coding-Decoding — Frequently Asked Questions
What is the first thing to check in a coding question?
Compare letter positions of the word and its code. A constant gap means a shift code; a variable but symmetric gap usually means reversal; no positional relation means substitution — then match letters across the given examples.
How are sentence-coding questions solved quickly?
Find a word that repeats across two coded sentences — its code is the token both code-sentences share. Eliminate word by word instead of decoding everything.
How many Coding-Decoding practice questions does Parikshala have for RRB Group D?
53 exam-pattern Coding-Decoding questions for RRB Group D Reasoning, each with a step-by-step solution. Practice is free — no sign-up needed to start.