UPSC CSE 2025 · PYQ · Series / Pattern Completion · medium
Consider the sequence AB_CC_A_BCCC_BBC_C which follows a particular pattern. Which one of the following completes this sequence ?
A.B, C, B, C, A✓ Correct
B.A, C, B, C, A
C.B, C, B, A, C
D.C, B, B, A, C
Explanation
Filling the blanks with option (a) B, C, B, C, A gives: ABBCCC ABBCCC ABBCCC AC — checking grouping ABB CC_ A_ BCCC _BBC_C. Trying option (a): AB B CC C A B BCCC A BBC C C — pattern emerges as repeating 'ABBCCC' blocks. The pattern ABBCCC repeats three times: ABBCCC|ABBCCC|ABBCCC, fitting perfectly with blanks filled as B, C, B, C, A. Hence option (a) is correct.
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