Opposite Letter Coding
Opposite Letter Coding replaces each letter with its mirror image in the alphabet, where A↔Z, B↔Y, C↔X, and so on. This is also known as the Atbash cipher. The relationship is: position of mirror letter = 27 - position of original letter.
What You'll Learn
Introduction to Opposite Letter Coding
Opposite Letter Coding replaces each letter with its mirror image in the alphabet, where A↔Z, B↔Y, C↔X, and so on. This is also known as the Atbash cipher. The relationship is: position of mirror letter = 27 - position of original letter.
Prerequisites
How to Solve Opposite Letter Coding Problems
Step 1: Convert the given letter to its position number (A=1, B=2, ..., Z=26)
Step 2: Calculate mirror position = 27 - original position
Step 3: Convert the mirror position back to a letter
Step 4: Apply this to each letter in the word
Step 5: For decoding, use the same formula (it is its own inverse)
Step 6: Verify the transformation is consistent for all letters
Step 7: Present the coded or decoded word
Example Problem
Example 1: Code 'CAT' using opposite letter coding (A↔Z, B↔Y). Solution: Step 1: C=3, A=1, T=20 Step 2: C: 27-3=24→X, A:27-1=26→Z, T:27-20=7→G Step 3: Coded word = XZG Answer: XZG Example 2: Decode 'XZG' using opposite letter coding. Solution: X=24→27-24=3→C, Z=26→27-26=1→A, G=7→27-7=20→T → CAT Answer: CAT
Pro Tips & Tricks
- Memorize: A↔Z, B↔Y, C↔X, D↔W, E↔V, F↔U, G↔T, H↔S, I↔R, J↔Q, K↔P, L↔O, M↔N
- The middle pair: M(13) ↔ N(14)
- Formula: Mirror letter = letter at position (27 - original position)
- Opposite coding is an involution (applying twice returns original)
- Vowels map to consonants: A(1)→Z(26), E(5)→V(22), I(9)→R(18), O(15)→L(12), U(21)→F(6)
- Common words: CAT→XZG, DOG→WLT, SUN→HFM
Shortcut Methods to Solve Faster
Common Mistakes to Avoid
Practice Worksheets
Practice makes perfect! Work through these worksheets to master Opposite Letter Coding. Each worksheet contains 20 questions with detailed explanations. Start from Worksheet 1 and progress through increasing difficulty levels.
Exam Importance
Opposite Letter Coding is an important topic for various competitive exams. Here's how frequently it appears:
Ready to Master Opposite Letter Coding?
Start with Worksheet 1 and work your way up to expert level! Each worksheet includes: