Common rules
- Shifting each letter forward or backward by a fixed number
- Reversing the word or its alphabet positions
- Replacing letters with numbers (A = 1, B = 2, and so on)
Worked examples
Example 1. If CAT is coded as DBU, each letter moves one place forward (C→D, A→B, T→U). So BOOK is coded as CPPL.
Example 2. With A = 1, B = 2 and so on, the code for BAD is 2-1-4.
Technique
Write the alphabet with numbers 1 to 26 at the top of your rough sheet, and its reverse underneath. Many questions then become a lookup. Combine with number series and see the usage in SSC CGL reasoning.
