Multiple choice

Which number is wrong in the following number series. 4, 6, 14, 51, 220, 1125, 6786

  1. 6

  2. 4

  3. 14

  4. 1125

  5. 6786
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A Correct answer
Explanation

The pattern of the series is that each term is multiplied by its position index and then the square of that index is added to it. Specifically, the formula is term(n) = term(n-1) * n + n^2. Applying this, the second term should be 4 * 1 + 1^2 = 5, making 6 the wrong number in the series.

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