Multiple choice general knowledge

245, 356, 487, 593, 638 - Odd man out

  1. 245

  2. 487

  3. 593

  4. 356
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

593 is the odd one out as it is the only prime number in the list. 245 = 5 × 7 × 7 (composite), 356 = 2 × 2 × 89 (composite), 487 = 3 × 7 × 23 (composite), and 638 = 2 × 11 × 29 (composite). Prime numbers have exactly two factors (1 and themselves), while composite numbers have more than two factors.

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