Multiple choice

Which number is wrong in the given series $1, 9, 25, 50, 81$.

  1. $1$
  2. $25$
  3. $50$
  4. $81$
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C Correct answer
Explanation

The series is 1^2, 3^2, 5^2, 7^2, 9^2. The values should be 1, 9, 25, 49, 81. 50 is the wrong number.

AI explanation

The terms in the series closely match the perfect squares of consecutive odd numbers. We see that 1 is 1 squared, 9 is 3 squared, 25 is 5 squared, and 81 is 9 squared. Following this clear pattern, the fourth term should be 7 squared, which is 49. The number 50 breaks this established sequence, making it the wrong number in the series.

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