Multiple choice

Find the wrong number in the following series. 5, 11, 24, 51, 106, 216, 440

  1. 24

  2. 51

  3. 106

  4. 216

  5. 440
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D Correct answer
Explanation

The pattern is: 5*2+1=11, 11*2+2=24, 24*2+3=51, 51*2+4=106, 106*2+5=217. The term 216 is incorrect; it should be 217.

AI explanation

The correct series should follow a pattern where each number is multiplied by 2, and then 1 is added to find the subsequent value. Multiplying 5 by 2 and adding 1 equals 11; multiplying 11 by 2 and adding 1 equals 23, not 24. Continuing the correct pattern, we double 23 and add 1 to get 47, double 47 and add 1 to get 95, and double 95 and add 1 to get 191. The result is 216.

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