Multiple choice

Each of the following number series one number is wrong. Find out the odd number. 1 123 292 517 806 1167 1608

  1. 1

  2. 292

  3. 1608

  4. 806

  5. 123
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A Correct answer
Explanation

The differences between consecutive terms are 122, 169, 225, 289, 361, 441. Except for the first difference (122), all others are perfect squares of odd numbers: 13²=169, 15²=225, 17²=289, 19²=361, 21²=441. The first difference should be 11²=121, meaning the first term should be 123-121=2, not 1.

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