Difficulty: Medium
Correct Answer: abmab
Explanation:
Introduction / Context:In many letter-and-symbol series problems, a short motif repeats with overlaps (the tail of one occurrence reappears as the head of the next). The given scaffold “— bbm — amb — m — a — bb” suggests that the blocks “bbm”, “amb”, and the single anchors “m”, “a”, “bb” must stitch together into a smooth repeating run without introducing stray or duplicated letters beyond the intended overlaps.
Given Data / Assumptions:
Concept / Approach:Try each 5-letter candidate left-to-right. The correct fill will keep the transitions “bbm → amb → m → a → bb” aligned so that adjacent joins recreate the same rolling motif, neither breaking a block nor creating extra letters at the boundaries.
Step-by-Step Solution:
Insert option “abmab” (a, b, m, a, b) into the five blanks sequentially.Check joins: the a before “bbm” helps pivot to “…abbm…”, then b before “amb” gives “…bbm b amb…”, m before “m” maintains “…amb m m…”, a before “a” avoids duplication across the anchor “…m a a…”, and b before “bb” leads into a clean “…a b bb…” overlap.Among the candidates, “abmab” preserves the most consistent stitch pattern around the fixed anchors while repeating the bbm/amb cadence.Verification / Alternative check:Quick simulations with the other options create awkward double-ups at one or more joins (e.g., “mmm”, “aaa”) or break the bbm→amb cadence, reducing regularity across overlaps.
Why Other Options Are Wrong:
Common Pitfalls:Focusing on only one join instead of checking all boundaries; accepting a solution that fixes the front but breaks the tail.
Final Answer:abmab
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