🚀 Quick Revision Sheet – Coding-Decoding
🔑 Golden Rule
“Treat letters as numbers (A=1 … Z=26) & play with ±1, ±2, reverse, opposite.”
đź“Ś 6 High-Frequency Patterns (Railway Favourite)
| Pattern Name |
Rule (Forward A→Z) |
Reverse (Z→A) |
Memory Trick |
| +1 (Forward) |
Each letter +1 |
-1 |
“Add 1 → Ahead” |
| +2 (Skip) |
Each letter +2 |
-2 |
“Skip a seat” |
| Reverse Word |
Whole word reversed |
Same |
“Mirror writing” |
| Opposite letter |
A↔Z, B↔Y … (sum=27) |
Same |
“27 minus position” |
| Vowel→Consonant shift |
V+1, C+2 (or vice-versa) |
— |
“Vowels are VIP (+1)” |
| Number code |
Position nos. concatenated |
Reverse digits |
“Read like barcode” |
🧠Mnemonics
- A-Z = 1-26 → “All Boys Can Dance … Zebra” (count on fingers).
- Opposite letter → AZ BY CX DW EV … (read pairs: A-Z, B-Y… sum 27).
- Reverse word → “LAP ↔ PAL” (think friend’s name).
🎯 3-Step Railway Method
- Spot pattern: look at 1st & last letter of given code.
- Convert to numbers (A=1…Z=26).
- Apply ±1, ±2, reverse, opposite → match with options.
📊 Quick Reference Table (A=1 … Z=26)
| Letter |
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
| No. |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
| Letter |
N |
O |
P |
Q |
R |
S |
T |
U |
V |
W |
X |
Y |
Z |
| No. |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
⚡ 10 Rapid-Fire MCQs
1. If CAT is coded as DBU, then DOG is?
**Answer:** EPH (+1 pattern)
2. If RAIL → 91812, then PARK → ?
**Answer:** 1611811 (position numbers)
3. If ZOO → ALL, then TOOL → ?
**Answer:** GLOO (opposite letter)
4. If 12345 → VWXYZ, then 5 → ?
**Answer:** Z (last letter)
5. If CUP → PCR, then PEN → ?
**Answer:** PGN (C-2, U-2, P-2 → reverse -2)
6. If EARTH → VIZGS, then PLANET → ?
**Answer：** KORMVG (opposite letter)
7. If 786 → PEN, then 687 → ?
**Answer:** NEP (digit swap)
8. If FLAG → GMBH, then CODE → ?
**Answer:** DPEF (+1 each)
9. If 5-12-1 → E-L-A, then 16-5-14 → ?
**Answer:** P-E-N
10. If WATER → XBUFS, then FIRE → ?
**Answer:** GJSF (+1 each)
🎯 30-Second Hack: Spot vowels first—Railway sets 70 % codes around vowel shifts.
BETA
