Multiple choice

In this question, a number series is given with one term missing. Choose the correct option that will continue the same pattern. 17, 19, 15, 23, 7, 39, ?

  1. 18

  2. -25

  3. 25

  4. 9
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B Correct answer
Explanation

The series is 17, 19, 15, 23, 7, 39. The pattern alternates: +2, -4, +8, -16, +32. The next step is -64. 39 - 64 = -25.

AI explanation

The series follows an alternating pattern of adding and subtracting increasing powers of 2. We calculate the differences as 17 + 2 = 19, 19 - 4 = 15, 15 + 8 = 23, 23 - 16 = 7, and 7 + 32 = 39. The next operation must be subtraction by 64, so 39 - 64 equals -25.

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