If ‘DELHI’ is coded as ‘FIRPS’ in a certain code language, then how will you…

Concept: Some coding-language puzzles use a positional increasing-shift cipher: each letter of the plain word is moved forward in the alphabet by an amount that grows steadily with its position — the first letter shifts the least and the last letter shifts the most. To code a new word, first find this per-position shift rule from the given example, then apply the identical rule letter by letter to the new word.

Application: Comparing DELHI with its code FIRPS position by position gives the following shifts:

1. 1st letter: D shifts by +2 to F

2. 2nd letter: E shifts by +4 to I

3. 3rd letter: L shifts by +6 to R

4. 4th letter: H shifts by +8 to P

5. 5th letter: I shifts by +10 to S

So the shift at position i is 2×i. JAIPUR has six letters, so positions 1 to 6 need shifts +2, +4, +6, +8, +10 and +12. Applying them:

1. 1st letter: J (+2) → L

2. 2nd letter: A (+4) → E

3. 3rd letter: I (+6) → O

4. 4th letter: P (+8) → X

5. 5th letter: U (+10), wrapping past Z, → E

6. 6th letter: R (+12), wrapping past Z, → D

Reading the shifted letters in order gives the code LEOXED.

Cross-check: Subtracting the same position-wise shifts from L, E, O, X, E, D restores J, A, I, P, U, R exactly, confirming the shift rule is consistent in both directions and that LEOXED is the code for JAIPUR.