Coding–decoding for SBI PO

Coding–decoding rewards a prepared eye. The rule behind a code is almost always one of six or seven patterns, and a candidate who has seen them all can spot the right one in about 20 seconds. A candidate who hasn't tries one guess after another and loses two minutes.

This guide gives you the tools, the patterns in the order to test them, and a practice set where every answer has been checked letter by letter.

How it is asked

• Letter coding: BANK is written as CZOJ. How is LOAN written?
• Condition-based coding: a letter is coded one way if it is a vowel and another way if it is a consonant.
• Number coding: a word is coded as a number built from its letter positions.
• Sentence (word) coding: several short sentences are coded as groups of code words, and you have to work out which code belongs to which word. This is the common mains version and usually comes as a set of four or five questions.

The tools

Know these without thinking:

• Positions: A = 1 to Z = 26. The anchors E J O T Y = 5, 10, 15, 20, 25 let you find any letter in two steps.
• Reverse positions: A = 26 … Z = 1. A letter's reverse position is 27 minus its position.
• Opposite letters: pairs whose positions add up to 27. 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.
• Wrap-around: one step back from A is Z, and one step forward from Z is A.

The order to test

1. Same shift for every letter? (+1, +2, −1 …)
2. Alternating shifts? (+1, −1, +1, −1)
3. Reversed first? Reverse the word, then check for a shift.
4. Opposite letters? Check whether code and word letters add to 27.
5. Vowels and consonants treated differently?
6. Split into halves? Each half reversed or shifted on its own.

Test the rule on every letter, not just the first two. Many wrong options are built to match the first two letters.

Worked examples

Example 1: alternating shifts. BANK is written as CZOJ. How is LOAN written?

• B → C (+1), A → Z (−1, wrapping round), N → O (+1), K → J (−1).
• Rule: +1, −1, +1, −1.
• LOAN: L + 1 = M, O − 1 = N, A + 1 = B, N − 1 = M.
• LOAN → MNBM.

Example 2: reverse, then shift. CASH is written as JUCE. How is FUND written?

• No single shift fits C → J and A → U. Reverse CASH to H S A C. Now H → J, S → U, A → C, C → E: +2 each.
• FUND reversed is D N U F. Add 2: F P W H.
• FUND → FPWH.

Example 3: opposite letters. DEBT is written as WVYG. How is BOND written?

• D (4) → W (23): 4 + 23 = 27. E → V, B → Y, T → G all add to 27 as well.
• BOND: B → Y, O → L, N → M, D → W.
• BOND → YLMW.

Example 4: vowels and consonants. In a code, every consonant moves one letter forward and every vowel moves one letter back. How is LOAN written?

• L is a consonant: M. O is a vowel: N. A is a vowel: one back from A wraps to Z. N is a consonant: O.
• LOAN → MNZO.

Example 5: number coding. CAB is coded as 6 and BAD as 7. What is the code for FEE?

• CAB: 3 + 1 + 2 = 6. BAD: 2 + 1 + 4 = 7. The code is the sum of the letter positions.
• FEE: 6 + 5 + 5.
• FEE → 16.

Example 6: sentence coding (mains style).

• "bank offers low rate" is coded as "ka mi to ze"
• "rate cut helps bank" is coded as "ze pu lo ka"
• "low cut good news" is coded as "mi pu ra ve"
• "good bank news" is coded as "ra ka ve"

The codes are not in the same order as the words. Match words that appear in several sentences with the codes those sentences share.

"good" and "news" appear together in both of their sentences, so one is ra and the other ve, but no sentence separates them. If a question asks for the code of "news", the answer is cannot be determined.

Common mistakes

• Fixing the rule from the first two letters. Check all of them.
• Doing the steps in the wrong order. Reverse-then-shift and shift-then-reverse can give different codes.
• Forgetting the wrap-around from A back to Z.
• Assuming word order matches code order in sentence coding.
• Guessing a pair that the sentences never separate. If two words always appear together, their codes cannot be split.

Practice set

Questions 6 and 7 use the sentence codes in Example 6.

1. Using the rule in Example 1, how is CASH written?
2. Using the rule in Example 2, how is GOLD written?
3. Using the rule in Example 3, how is LOAN written?
4. Using the rule in Example 4, how is TRADE written?
5. If BANK is coded as 28 by the rule in Example 5, what is the code for FUND?
6. What is the code for "helps"?
7. What is the code for "good"?
8. CREDIT is written as ERCTID. How is MARKET written?

Answers:

1. DZTG. C + 1, A − 1 (wraps to Z), S + 1, H − 1.
2. FNQI. Reverse GOLD to D L O G, then add 2 to each letter.
3. OLZM. L (12) → O (15), O → L, A → Z, N → M. Each pair adds to 27.
4. USZED. T → U and R → S (consonants, forward). A → Z (vowel, back, wrapping). D → E (consonant). E → D (vowel).
5. 45. F 6 + U 21 + N 14 + D 4. Check: BANK is 2 + 1 + 14 + 11 = 28.
6. lo. "helps" appears only in sentence 2, and every other code there is fixed.
7. Cannot be determined. "good" is ra or ve; no sentence separates it from "news".
8. RAMTEK. CREDIT splits into CRE and DIT, and each half is reversed: ERC and TID. MARKET splits into MAR and KET, which become RAM and TEK.

What to do next

• Learn the opposite-letter pairs until you can recite them in 15 seconds.
• Solve 15 letter-coding questions a day for a week, testing the six patterns in order.
• Do one sentence-coding set a day, filling in a word-and-code table every time.
• Coding shows up inside other topics too: see data sufficiency in reasoning and the reasoning plan.