Multiple choice

In the following number series one number is given wrong, find the number? 380.25, 306.25, 240.25, 182.25, 112.25

  1. 380.25

  2. 240.25

  3. 182.25

  4. 306.25

  5. 112.25
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E Correct answer
Explanation

The series represents squares of consecutive half-odd numbers (19.5, 17.5, 15.5, 13.5, 11.5): (19.5)^2 = 380.25, (17.5)^2 = 306.25, (15.5)^2 = 240.25, (13.5)^2 = 182.25, (11.5)^2 = 132.25. The differences between consecutive squares are 74, 66, 58, 50 - decreasing by 8 each time. The last term should be 132.25, not 112.25.

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