Coding - Decoding
🔒 Log in to trackCoding questions reveal how a word (or sentence) is transformed into a code and ask you to apply the same transformation to a new word. CGL asks 3-5 per shift. Rules are mechanical: letter shifts, opposites, reversal, position sums, renames. Compute the rule from the sample pair, then apply it without creativity.
One page per subtopic: detailed notes, every question type, formulas, tricks and practice sets.
Every formula on one printable page, grouped by subtopic.
4 exam-level questions worked step by step.
93 questions — untimed practice or a timed test with analysis.
Track record in the exam
Questions per shift in recent SSC CGL papers.
Test difficulty mix (93 questions)
Question patterns exams keep repeating
Taken from previous-year papers. If a pattern is marked "very common", expect to see it in your exam.
Shift the letters
very commonA word and its code are given, like 'PEN is written as RGP'.
Find how far each letter moved in the sample.
Move the new word's letters the same way.
If PEN is written as RGP, how is RING written?
P→R, E→G, N→P: each letter moves +2
R+2 = T, I+2 = K
N+2 = P, G+2 = I
Answer: TKPI
Find the original word
commonA code is given and you must find the real word.
Find the rule from the sample.
Do the opposite of the rule to decode.
If PEN is written as RGP, which word is written as TKPI?
The rule is +2, so decode with −2
T−2 = R, K−2 = I
P−2 = N, I−2 = G
Answer: RING
Reverse the word and shift
commonThe code looks like the word read backwards, or backwards with a shift.
Find the shift and whether the word was reversed.
Do the same steps, in the same order, on the new word.
If GOLD is written as EMPH, how is SILK written?
GOLD shifted +1 = HPME, reversed = EMPH ✓
SILK shifted +1 = TJML
Reverse TJML
Answer: LMJT
Opposite letters
commonEach code letter and its real letter add up to 27 (A↔Z, B↔Y, M↔N).
Check that two letter pairs add up to 27.
Replace each letter of the new word by its opposite.
If MILK is written as NROP, how is CAKE written?
M(13) + N(14) = 27, I(9) + R(18) = 27, so letters become their opposites
C↔X, A↔Z
K↔P, E↔V
Answer: XZPV
Word to number
very commonA word gives a number, like 'BAT = 23'.
Add the place numbers of the letters (A = 1, B = 2 ...).
Compare with the given number and apply the same rule.
If BAT = 23, what is CAR?
B + A + T = 2 + 1 + 20 = 23, so the rule is: add the place numbers
C + A + R = 3 + 1 + 18
Answer: 22
Changed names
common'Milk is called water, water is called juice ...' followed by a normal question.
First answer the question in the normal way.
Then give the new name of that answer.
If milk is called water, water is called juice and juice is called tea, what do we drink when thirsty?
Normally, we drink water when thirsty
In this code, water is called juice
Answer: Juice
Code words in sentences
very commonTwo or three coded sentences, and you must find the code of one word.
Find the code words that appear in both sentences and match the common words.
The code word left over is the answer.
'sun is hot' = 'ta mo ri' and 'sun is bright' = 'ri ze mo'. What is the code for 'bright'?
Common words: 'sun is'
Common codes: 'ri' and 'mo'
In the second sentence, only 'ze' is left
Answer: ze
Letters to digits or symbols
commonLetters are replaced by digits or symbols, and some coded words are given.
Match each letter with its digit in the order they come.
Use a letter that appears in both words to check.
If ROSE = 6821 and SORE = 2861, what is the code for O?
ROSE = 6821 gives R = 6, O = 8, S = 2, E = 1
Check SORE = 2, 8, 6, 1 ✓
So O is the digit in second place
Answer: 8
Letters rearranged
occasionalThe code has the same letters as the word, but in a new order.
Compare the two words to see which letters swapped places.
Do the same swaps on the new word.
If PLANET is written as LPNATE, how is FOREST written?
PLANET → PL, AN, ET → LP, NA, TE
Each pair of letters is swapped
FOREST → FO, RE, ST → OF, ER, TS
Answer: OFERTS