Multiple choice

Find the missing number in the given number series. 4, 9, 17, ?, 69, 139, 277

  1. 28

  2. 42

  3. 35

  4. 51

  5. 63
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C Correct answer
Explanation

The pattern alternates between multiplying by 2 and adding 1, then multiplying by 2 and subtracting 1: 4×2+1=9, 9×2-1=17, 17×2+1=35, 35×2-1=69, 69×2+1=139, 139×2-1=277. The missing number is 35. Options like 28, 42, or 51 don't fit this alternating operation pattern.

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