Number series (find the wrong term): 40960, 10240, 2560, 640, 200, 40, 10 Spot the single incorrect term and describe the division pattern being followed.
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A640
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B40
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C200
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D2560
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E10240
Answer
Correct Answer: 200
Explanation
Introduction / Context:Decreasing sequences are often built by repeated division by a fixed number. We will check for a consistent divisor across the list and identify the term that breaks the pattern.
Given Data / Assumptions:
- Series: 40960, 10240, 2560, 640, 200, 40, 10
- Exactly one term is wrong.
Concept / Approach:Test division by 4 (a common base-2 friendly factor): 40960/4 = 10240, 10240/4 = 2560, 2560/4 = 640. Continue to see if all terms comply.
Step-by-Step Solution:40960 → 10240: ÷4 ✔10240 → 2560: ÷4 ✔2560 → 640: ÷4 ✔640 → next should be 160 (÷4), but the series shows 200 ✖Continuing from the corrected 160: 160 → 40 (÷4) ✔; 40 → 10 (÷4) ✔
Verification / Alternative check:With 200 replaced by 160, the whole series becomes a perfect repeated division by 4.
Why Other Options Are Wrong:
- 10240, 2560, 640, 40, 10: All lie on the exact ÷4 trajectory from the starting value.
- 200: The single value that does not equal the previous term divided by 4.
Common Pitfalls:Some solvers try alternating divisors prematurely. Always check the simplest single-divisor pattern first.
Final Answer:200