Multiple choice

Directions: Find the wrong number in the following number series. 5, 106, 209, 314, 420, 530, 641

  1. 641

  2. 530

  3. 420

  4. 209

  5. 106
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C Correct answer
Explanation

The differences are: 106-5=101, 209-106=103, 314-209=105, 420-314=106. The pattern of differences should be 101, 103, 105, 107, 109. 314 + 107 = 421, not 420. Thus 420 is the wrong number.

AI explanation

The differences between the consecutive numbers are 101, 103, 105, 106, 110, and 111. The pattern of differences should be consecutive prime numbers (101, 103, 105 is not prime), but assuming differences of consecutive odd numbers starting from 101, the sequence should be 101, 103, 105, 107, 109, and 111. Based on this pattern, 5 + 106 = 111, so 314 + 107 = 421 instead of 420, making 420 the wrong number.

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