Multiple choice

In each of the following number series, the wrong number is given, find out that number. 7, 11, 27, 61, 127, 227

  1. 227

  2. 127

  3. 61

  4. 11

  5. 27
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The pattern is x_n = 2 * x_{n-1} + 1, 3, 5, 7... specifically: 7*2-3=11, 11*2+5=27, 27*2+7=61, 61*2+9=131. The sequence follows a pattern of adding consecutive odd numbers or powers of 2. The term 61 is incorrect as the sequence should be 7, 11, 27, 59, 127.

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