Number series – find the wrong term (add consecutive odd cubes): 274, 301, 426, 769, 1498, 2824, 5026 Exactly one term breaks the pattern “next = previous + k^3” with k = 3, 5, 7, 9, 11, 13, … Identify the incorrect entry.

Difficulty: Hard

Correct Answer: 2824

Explanation:


Introduction / Context:
“Find the wrong term” problems require detecting a clean rule that all but one term obeys. A neat and test-friendly rule here is adding consecutive odd cubes to progress through the sequence, a variant that rapidly increases numbers while staying simple to verify.



Given Data / Assumptions:

  • Proposed rule: add 3^3, 5^3, 7^3, 9^3, 11^3, 13^3, … to get successive terms.
  • Start: 274.


Concept / Approach:
Check each step against the odd-cube increments; any single mismatch flags the wrong term, which we minimally correct under the Recovery-First policy.



Step-by-Step Solution:

274 + 3^3 = 274 + 27 = 301 ✓301 + 5^3 = 301 + 125 = 426 ✓426 + 7^3 = 426 + 343 = 769 ✓769 + 9^3 = 769 + 729 = 1498 ✓1498 + 11^3 = 1498 + 1331 = 2829 ✗ (listed as 2824 → off by −5)Continuing would be 2829 + 13^3 = 2829 + 2197 = 5026 ✓


Verification / Alternative check:
The sequence is perfectly consistent if 2824 is replaced by 2829 (i.e., +11^3). All other steps check out exactly.



Why Other Options Are Wrong:

301, 426, 769 conform to +27, +125, +343 respectively; 2824 alone breaks the +1331 step.


Common Pitfalls:
Missing that both 5026 and earlier terms still fit the odd-cube rule if the single typo is corrected.



Final Answer:
2824

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