Coding-Decoding — Complete Concept Guide for SSC CGL 2026

Coding-Decoding tests your ability to detect the rule used to encode a word or number, then apply that rule to decode another. This is one of the most scoring topics in SSC CGL Reasoning.

Common Coding Types

  • Letter Shifting: Each letter shifts by a fixed number (A+3=D).
  • Reverse Alphabet: A=Z, B=Y, C=X...
  • Number Coding: A=1, B=2... or A=26, B=25...
  • Symbol Coding: Letters replaced by symbols or special characters.
  • Conditional Coding: Rules apply based on position of letters.

Tricks & Shortcuts

  • Always check the first and last letter patterns first.
  • Calculate the difference (shift) for 2–3 letter pairs to confirm the rule.
  • For number coding, check if the code = letter position, reverse position, or letter position × 2.

⚡ Key Tricks for SSC CGL

  • Always read the question stem carefully before looking at options.
  • Eliminate wrong answers systematically — it saves time.
  • In SSC CGL, most Coding-Decoding questions are solvable in under 45 seconds with practice.

Practice MCQs — Coding-Decoding (10 Questions)

Q1. If CAT = 3120, then DOG = ?

A. 4157 B. 41523 C. 4152 D. 4715

Q2. In a code, MANGO=13 and APPLE=15. Then GRAPE=?

A. 17 B. 14 C. 16 D. 18

Q3. TRAIN is coded as USBJB. What is coded as ESJWF?

A. DRIVE B. DRIFT C. DRIVE D. DRONE

Q4. If WATER = XCVGT, then FLAME = ?

A. GNCOG B. GNCOF C. HNDOF D. GNDOF

Q5. SCHOOL = SFIPPM. TEACH = ?

A. UFBDI B. UDBFH C. UFBDH D. UFBCH

Q6. In a code, 1=A, 2=B... then what is 20-5-1-3-8-5-18?

A. TEACHER B. TEACHES C. SCIENCE D. STUDENT

Q7. If LOTUS is coded as MPWVT, then TIGER is coded as?

A. UJHFS B. UKHFS C. UJGFS D. UJHES

Q8. In mirror coding, A=Z, B=Y... then CAB = ?

A. XZY B. YZX C. ZYX D. XYZ

Q9. If STRONG = 6 and POWER = 5, then INTELLIGENCE = ?

A. 12 B. 14 C. 13 D. 11

Q10. BEAD is coded as 2514. What is FADE coded as?

A. 6145 B. 6154 C. 6514 D. 1645

Improve your Coding-Decoding score with GPT Sir's SSC CGL books — featuring AI-generated explanations and unlimited practice tests!