Classification – Odd one out (multiple of 5 vs not) Three of the following end with 0 and are multiples of 5 and 10. Identify the number that does not fit this pattern and mark it as the odd one out.
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A168
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B120
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C290
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D380
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ENone of these
Answer
Correct Answer: 168
Explanation
Introduction / Context:This classification item focuses on detecting a shared divisibility trait. Numbers ending in 0 are multiples of 10 (and of 5). The odd one out will be the number that fails to share this clear surface-level property.
Given Data / Assumptions:
- Options: 120, 168, 290, 380
- We examine terminal digit patterns and divisibility by 5/10.
Concept / Approach:A number is a multiple of 10 if it ends in 0; multiples of 10 are also multiples of 5. Therefore, checking the last digit is sufficient: 0 implies multiple of 10; 5 implies multiple of 5; other endings imply neither.
Step-by-Step Solution:120 ends with 0 → multiple of 10 (thus of 5).290 ends with 0 → multiple of 10 (thus of 5).380 ends with 0 → multiple of 10 (thus of 5).168 ends with 8 → not a multiple of 10 or 5.
Verification / Alternative check:Divisibility by 5 requires last digit 0 or 5. Only 168 fails this basic test, confirming it as the odd element.
Why Other Options Are Wrong:
- 120: Multiple of 10 and 5 → fits the pattern.
- 290: Multiple of 10 and 5 → fits the pattern.
- 380: Multiple of 10 and 5 → fits the pattern.
- None of these: There is a unique odd one out (168).
Common Pitfalls:Overthinking with prime factors; this task is solved fastest by a last-digit check. Do not confuse being even (like 168) with being a multiple of 5/10.
Final Answer:168