Multiple choice

Find the wrong number in the following number series. 223, 287, 359, 439, 529, 623

  1. 439

  2. 287

  3. 623

  4. 529

  5. 359
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D Correct answer
Explanation

The series is 223, 287, 359, 439, 529, 623. Differences: 64, 72, 80, 90, 94. The differences should be 64, 72, 80, 88, 96. 529 is incorrect because 439 + 88 = 527.

AI explanation

The differences between the terms are perfect squares. The differences are 64, 72, 80, 90 and 94, which do not form perfect squares, but rather an increasing sequence; however, the actual pattern is 223 plus 64 equals 287, 287 plus 72 equals 359, 359 plus 80 equals 439, and 439 plus 90 should be 529. The correct difference should be 81, making the term 520; since 520 plus 100 equals 620, the term 529 is the anomaly. Therefore, 529 is the wrong number.

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