Difficulty: Easy
Correct Answer: 30
Explanation:
Introduction / Context:
Arithmetic-difference ladders where the increment grows by 1 each time are extremely common. Recognizing the ladder saves time.
Given Data / Assumptions:
Concept / Approach:
Apply the next increment (+6) to the latest term to get the next value.
Step-by-Step Solution:
Verification / Alternative check:
Extending further would continue +7, +8, … forming a smooth progression.
Why Other Options Are Wrong:
Common Pitfalls:
Overcomplicating with powers; the simple ladder fits perfectly.
Final Answer:
30
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