In the series 2880, 480, 92, 24, 8, 4, 4, which term is wrong?

Difficulty: Medium

Correct Answer: 92

Explanation:


Introduction / Context:
This is an odd term detection question in a descending series that appears to involve division by successively smaller integers. The task is to reconstruct the intended pattern and identify which term does not fit.


Given Data / Assumptions:

  • Series: 2880, 480, 92, 24, 8, 4, 4.
  • Exactly one term is incorrect.
  • The series is expected to follow a neat division rule.


Concept / Approach:
When a series decreases significantly from term to term, it often involves division by an integer factor. A typical pattern is division by 6, then by 5, then by 4, then by 3, then by 2, then by 1. We can test whether this structure applies.


Step-by-Step Solution:
Step 1: Check the first two terms: 2880 / 6 = 480. So a natural first step is division by 6. Step 2: Next, if we divide by 5: 480 / 5 = 96, but the series gives 92. This suggests 92 is suspicious. Step 3: Continue the hypothetical correct pattern: from 96 divide by 4 to get 96 / 4 = 24, which matches the next term. Step 4: Then divide by 3: 24 / 3 = 8, which matches the next term. Step 5: Next divide by 2: 8 / 2 = 4, again matching the series. Step 6: Finally, division by 1 keeps the last term as 4, so the final 4 is also consistent. Step 7: Therefore, the only incorrect term is 92, which should have been 96 to follow the division pattern by 6, 5, 4, 3, 2, and 1.


Verification / Alternative check:
If we rewrite the corrected series as 2880, 480, 96, 24, 8, 4, 4, the operations between terms are: divide by 6, divide by 5, divide by 4, divide by 3, divide by 2, then divide by 1. This is a clear and elegant rule and uses each integer from 6 down to 1 exactly once. The given term 92 is the only one that breaks this pattern.


Why Other Options Are Wrong:
480, 24, and 4 all fit perfectly in the division chain. If any of them were replaced, we could not retain the simple successive division rule. Only 92 fails to equal the expected result of 480 divided by 5.


Common Pitfalls:
Candidates might incorrectly attempt subtraction or mixed operations and end up with complicated schemes. Another pitfall is to accept near matches like 92 instead of noticing that 96 would make the pattern perfect. In number series questions, patterns that use consecutive integers as divisors or multipliers are very common, so they are worth checking first.


Final Answer:
The wrong term in the given series is 92.

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