IMU CETGeneral AptitudeCoding Decoding
🧠 General Aptitude

Coding Decoding

40 marks in IMU CET
120 questions in bank
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📖 What IMUCET Tests from Coding Decoding

Listen up, junior. Out at sea, clear communication is the difference between a smooth voyage and a disaster in the engine room. If a receiver gets a garbled message or a coded alarm, you need to decode it instantly. That is exactly why the Indian Maritime University Common Entrance Test (IMUCET) tests you on Coding-Decoding. They want to see if you can spot patterns, think logically, and keep your head cool under time pressure.

In this topic, words, numbers, or symbols are encrypted using a specific rule. Your job is to crack that rule and apply it to a new word. Most students mess this up because they try to solve it in their heads or panic and lose track of the alphabet order. Treat this like tracing a pipeline: find the source, follow the flow, and you will reach the correct valve every single time.

🎯 IMUCET Focus
IMUCET specifically targets letter-to-letter shifting (like moving +3 or -2 steps), letter-to-number coding (using direct or reverse alphabetical ranks), and direct symbol substitution. They love using maritime terms like SHIP, DECK, CREW, or PORT to test these patterns. Focus on mastering the reverse-letter positions and the EJOTY shortcut to save precious seconds.
MARKS WEIGHTAGE
You can expect 2 to 4 questions from Coding-Decoding in the General Aptitude section of IMUCET.
🧠 Key Concepts
Forward and Reverse Alphabet Ranks
Every letter has a forward rank (A=1, Z=26) and a reverse rank (A=26, Z=1). Remember that the sum of the forward and reverse ranks of any letter is always 27.
The EJOTY Speed Tool
Memorize the word EJOTY where E=5, J=10, O=15, T=20, and Y=25. This acts as your mental anchor to quickly find the position of any letter without counting from A every time.
Opposite Letter Pairs
Letters that pair up from opposite ends of the alphabet (A-Z, B-Y, C-X) are common in codes. You can find a letter's opposite by subtracting its position from 27.
⚡ What to Skip
If your exam is just two weeks away, you can safely skip complex matrix-based coding and long conditional coding paragraphs. Focus 100% on basic letter-to-number shifts and reverse-position coding, as these make up 90% of the questions.
🏆 Exam Strategy
As soon as you get your rough sheet, write down A to M and directly below it write N to Z with their numbers 1 to 26. This visual map prevents mental fatigue and silly mistakes. Always check the first and last letters of the options first to eliminate wrong answers instantly. If a pattern does not click within 30 seconds, flag it, move to the next question, and come back to it later.
🌳 Understand This Topic in Depth▼ Expand
📊 Visual Reference
THE CHIEF ENGINEER'S DECODING TOOLKIT1. THE EJOTY ANCHOR SYSTEM (FORWARD POSITIONS)E5J10O15T20Y252. REVERSE POSITION RULE (SUM = 27)Forward Rank + Reverse Rank = 27Example for Letter 'D' (Forward = 4):Reverse Rank = 27 - 4 = 23Pro-Tip: Write this mapping on your rough sheet before the exam starts!
This diagram illustrates the EJOTY anchor system for quick letter positioning and the mathematical rule to find reverse alphabetical ranks instantly.
✏️ Worked Example
In a secure maritime communication system, the word 'CREW' is coded as '249224'. How will the word 'DECK' be coded under the same system?
Speed Tip
Do not calculate the entire code. Look at the first letter 'D' (reverse is 23) and the last letter 'K' (reverse is 16). Scan the options immediately. Only one option will start with 23 and end with 16. Mark it and move on!
✅ Quick Check — Before You Practice

Answer these 3 questions to confirm you understood the key concepts above.

Q1. In a certain code language, 'PORT' is written as '16151820'. How will 'SHIP' be written in that same language?
A. 198916
B. 1918916
C. 188916
D. 1981916
Q2. If 'CREW' is coded as 'FUDZ' by shifting each letter forward by 3 positions, how will 'DECK' be coded under the same rule?
A. GHFN
B. GHFM
C. GHDN
D. FIEL
Q3. If 'A' is coded as 26, 'B' as 25, and 'C' as 24, what will be the code for the word 'HALO'?
A. 19261512
B. 19251512
C. 19261412
D. 18261512
🌳 Understand This Topic in Depth▼ Expand
📝 Practice Questions — Coding Decoding
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