If ZERO is encoded as ADSN, then how do you encode STOP?

Answer: (b) TSPO

Letters shift alternately forward and back by one: Z → A (+1), E → D (−1), R → S (+1), O → N (−1). Applying +1, −1, +1, −1 to S, T, O, P gives T, S, P, O.

1. Z + 1 = A, E − 1 = D, R + 1 = S, O − 1 = N.
2. S + 1 = T, T − 1 = S, O + 1 = P, P − 1 = O.
3. STOP → TSPO.

Remember · Coding items: write the shift for each letter position; alternating patterns are common.

Question and answer: UPSC's provisional GS Paper II (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). · Report an error