Prelims 2026 · CSAT / Logical Reasoning · Question 18
A pattern formed by two characters a and b is repeated more than once in the following string :<br/><br/>x b x a x a x x a x a x b a b<br/><br/>What is x x in the 7th and 8th positions from the left in the above string?<br/>
Answer
bb
Treat the 15-character string as 3 equal blocks of 5: (1–5), (6–10), (11–15). Matching positions across the three blocks gives the repeated pattern as ABBAB. Hence positions 7 and 8 are B and B.