If GRAND is coded as RGADN, then NOBLE is coded as

Concept: In letter-coding-decoding puzzles, the letters of a word are rearranged according to a fixed positional rule (which positions swap and which stay fixed) — it is not a shift or substitution cipher. Find this rule from the given example, then apply the same rule to the new word.

Applying the rule:

1. Write GRAND with position numbers: G(1) R(2) A(3) N(4) D(5).

2. Its given code is RGADN: R(1) G(2) A(3) D(4) N(5).

3. Comparing position by position: positions 1 and 2 swap (G↔R), position 3 (A) stays unchanged, and positions 4 and 5 swap (N↔D).

4. So the rule is: swap the 1st and 2nd letters, keep the 3rd letter fixed, swap the 4th and 5th letters.

5. Apply the same rule to NOBLE: N(1) O(2) B(3) L(4) E(5).

6. Swap 1st and 2nd: O, N. Keep the 3rd letter B unchanged. Swap 4th and 5th: E, L.

7. Result: O-N-B-E-L, i.e. ONBEL.

Cross-check: Re-apply the same rule to the original word GRAND: swapping 1st/2nd gives R,G; A stays fixed; swapping 4th/5th gives D,N — that reproduces R-G-A-D-N (RGADN), exactly the given example, confirming the rule before trusting it on NOBLE.