Difficulty: Easy
Correct Answer: 19 35
Explanation:
Introduction / Context:
This series alternates two behaviors: an increasing subsequence and a fixed repeating value that appears at regular positions. Recognizing the period of the fixed term is key.
Given Data / Assumptions:
Concept / Approach:
Note that every third term is 35, while the other terms form their own +2 progression across non-multiple-of-3 indices.
Step-by-Step Solution:
Verification / Alternative check:
Check back: positions 1,2,4,5,7 follow +2 steps, and 3,6,9 are constant at 35. The pattern is fully consistent.
Why Other Options Are Wrong:
Common Pitfalls:
Forgetting to check positional periodicity; not all patterns are simple differences—some embed a repeating constant at fixed intervals.
Final Answer:
19 35
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