Difficulty: Medium
Correct Answer: 366
Explanation:
Introduction / Context:
Some non-linear series are governed by a recurrence on the differences, not the terms. Recognizing and extending that difference-recurrence gives the next value directly.
Given Data / Assumptions:
Concept / Approach:
Model the first differences. Test d2=2*3+2=8; d3=8*3+2=26; d4=26*3+2=80. The fit is exact, so extend once more using the same rule.
Step-by-Step Solution:
Verification / Alternative check:
Back-substitute differences to reconstruct all terms; the recurrence holds at each step.
Why Other Options Are Wrong:
Common Pitfalls:
Trying multiplicative ratios on the terms; here the hidden structure is in the differences.
Final Answer:
366
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