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.

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:

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.