Multiple choice

Directions: In the following number series, one number is wrong. Find out the wrong number. 1, 9, 35, 91, 189, 343

  1. 1

  2. 9

  3. 35

  4. 343

  5. 189
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D Correct answer
Explanation

The series is 1, 9, 35, 91, 189, 343. Differences: 8, 26, 56, 98, 154. Second differences: 18, 30, 42, 56. The pattern of second differences should be 18, 30, 42, 54. The last term 343 is incorrect.

AI explanation

The given series follows the pattern of consecutive cubes and square numbers: 0 cubed plus 1 is 1, 2 cubed plus 1 is 9, 3 cubed plus 8 is 35, 4 cubed plus 27 is 91, and 5 cubed plus 64 is 189. The final term should be 6 cubed plus 125, which equals 341. Since the given number is 343, it is the wrong number in the series.

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