Number series (find the wrong term): 8, 14, 26, 48, 98, 194, 386

Difficulty: Medium

Correct Answer: 48

Explanation:


Introduction / Context:
This is a number-series error-detection question. You are given a sequence and must spot the single term that breaks an otherwise consistent rule. Such questions test your ability to see hidden patterns like fixed increments, geometric growth, or patterned differences.


Given Data / Assumptions:

  • Series: 8, 14, 26, 48, 98, 194, 386.
  • Exactly one term is incorrect.
  • Look for a consistent pattern across all valid transitions.


Concept / Approach:
First check simple recurrences. The consecutive differences are key: compute each difference and see if those differences follow a rule (for instance, doubling). If a single step violates the discovered rule, that term is the outlier.


Step-by-Step Solution:
Compute differences: 14−8=6, 26−14=12, 48−26=22, 98−48=50, 194−98=96, 386−194=192.Notice a near-doubling pattern for the increments: starting from 6, doubling gives 6, 12, 24, 48, 96, 192.Compare with actual: 6, 12, 22, 50, 96, 192. The third and fourth increments should be 24 and 48, not 22 and 50.If the third increment were 24, the third term would be 26+? No, apply from the second term: 14 + 12 = 26 (correct), then +24 = 50 (so the next term should be 50, not 48). Thereafter +48 = 98 (which matches), +96 = 194, +192 = 386.Therefore, the lone inconsistent term is 48 (it should be 50 under the doubling-difference rule).


Verification / Alternative check:
Repaired series: 8, 14, 26, 50, 98, 194, 386 with differences 6, 12, 24, 48, 96, 192 (perfect doubling). Only the third term 48 → 50 correction fixes all later terms without further edits.


Why Other Options Are Wrong:

  • 14, 98, 194, 386 all fit the repaired doubling-difference structure.


Common Pitfalls:

  • Looking for a multiply-by rule and missing the clear pattern in the differences.
  • Changing multiple terms; the task is to identify a single wrong value.


Final Answer:
48

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