Find the odd number: Among 143, 171, 117, and 195, three are multiples of 13 while one is not. Identify the non-multiple of 13.

Difficulty: Easy

Correct Answer: 171

Explanation:

Introduction / Context:This classification tests recognition of multiples of 13. The single non-multiple is the outlier.

Given Data / Assumptions:

  • 143 = 11 * 13; 117 = 9 * 13; 195 = 15 * 13.
  • 171 is close to 13 * 13 = 169 but is not equal.

Concept / Approach:Compare each candidate with nearby products of 13.

Step-by-Step Solution:

143 → multiple of 13.117 → multiple of 13.195 → multiple of 13.171 → not a multiple of 13 (169 and 182 are the adjacent multiples).

Verification / Alternative check:171 ÷ 13 ≈ 13.153… non-integer; hence not divisible by 13.

Why Other Options Are Wrong:They are exact multiples of 13.

Common Pitfalls:Confusing proximity (171 near 169) with exact divisibility.

Final Answer:171 is not a multiple of 13 and is the odd number.

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