Coding – Decoding

 

Coding-Decoding – Preparation Guide

What is Coding-Decoding? Coding-Decoding is a logical reasoning topic frequently asked in competitive and entrance exams like CUET, SSC, Banking, Railways, and other aptitude-based tests. It tests a student’s ability to understand patterns, relationships, and logic behind words, numbers, or symbols.

Types of Coding-Decoding Questions

1. Letter Coding Words are coded using certain alphabetical patterns. Example: If CAT is coded as DBU, then DOG is coded as?
2. Number Coding Words are coded with numbers. Example: If PEN = 35, INK = 34, then what is the code for PAPER?
3. Symbol Coding Symbols replace words or vice versa. Example: If @ means +, # means -, then solve: 10 # 2 @ 4 = ?
4. Substitution Coding One thing is substituted with another name. Example: If ‘Red’ means ‘Blue’, ‘Blue’ means ‘Green’, what is the color of the sky?
5. Mixed Letter Coding Several sentences are coded together to find the meaning of a particular word. Example: Based on given code statements, decode the meaning of certain words.

Tips to Solve Coding-Decoding Questions

Understand the Pattern: Check whether the logic is based on:

• Alphabet position (A = 1, B = 2…)
• Reverse alphabet (Z = 1, Y = 2…)
• Shifting (forward or backward)
• ASCII values (advanced level)

Break the Word: Split the word into letters and analyze each part. Write Positions of Letters: This helps in quickly spotting the shift in alphabets. Practice Reverse Coding: Be ready to decode from code back to original. Keep Note of Repetition: If a word appears multiple times with different codes, look for patterns. Eliminate Options: In MCQs, often eliminating wrong choices leads you to the right one. Avoid Assumptions: Stick to the logic shown in the question. Never apply general meaning.

Common Mistakes to Avoid

Overthinking – Don’t look for complex patterns if simple logic works. Skipping practice – Coding-Decoding requires regular practice to get comfortable. Ignoring options – Many questions can be solved quickly by testing the given options. Confusing position values – Always double-check your A=1 to Z=26 placement.

Quick Practice Example

If TRUST = UVSUT, then how is FAITH coded?

Solution Tip:

Check if one letter is changing while the rest remain the same.

Final Strategy

Practice different types regularly Time yourself while solving Focus on accuracy over speed initially Prepare short notes of common patterns