Types seen recently
- Sentence (word) coding: "'bank loan offer good' is written as 'mo ki ta zu'..." - find the code of a word (most common in 2022-2025 papers).
- Letter shifting: each letter moved by a fixed or changing number (generated on this site).
- Letter-digit substitution: ROSE = 6821, CHAIR = 73456, find SEARCH.
- Digit-symbol coding with conditions (Mains): a table of codes plus rules like "if the first digit is odd and the last is even, interchange their codes".
Sentence-code method
- List the sentences one below the other.
- For a word that appears in two or more sentences, its code is the code common to all those sentences.
- Remove the codes you have fixed, and the leftovers in each sentence give the remaining words.
- If two words appear together in exactly the same sentences, their codes cannot be separated - the answer is "either X or Y" or "cannot be determined".
Worked example
| Sentence | Code |
|---|---|
| pen and ink | li mo su |
| ink is blue | su pa ri |
| blue and red pen | ri li mo ta |
'ink' (sentences 1 and 2) = su. 'blue' (sentences 2 and 3) = ri, so 'is' = pa. 'pen' and 'and' both appear only in sentences 1 and 3, sharing li and mo - they cannot be told apart. In sentence 3 the leftover code ta = 'red'.
Conditional digit coding
- Write the plain code of every digit first.
- Check the conditions in the order given; apply only the one that fits (first/last digit odd or even is the usual test).
- If no condition applies, the plain code is the answer.
Letter-digit substitution
When words are given with digit codes (ROSE = 6821, CHAIR = 73456), the codes usually follow letter by letter in the same order. Build a two-row table of letters and digits from the first word, confirm with the second word (a repeated letter, here R = 6, must get the same digit), and then read off the new word. If a letter of the new word never appeared in the given words, the code cannot be determined.
Time target
Sentence-code sets: 2-3 minutes for five questions once the table is built. Conditional coding: 30-40 seconds per question.