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AFCAT Number Series — practice questions

Explore 12 free Number Series questions in AFCAT General Intelligence and Reasoning. Open each question or exercise to read its content, reference answers and available explanation.

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Number Series questions and exercises with answers

Showing questions 1–12 of 12.

Find the next number: 2, 6, 12, 20, 30, ?Read the answer and worked solution →Find the next number: 1, 4, 9, 16, 25, ?Read the answer and worked solution →Find the next: 3, 7, 15, 31, 63, ?Read the answer and worked solution →Find the next: 1, 1, 2, 3, 5, 8, ?Read the answer and worked solution →Find the missing: 5, 11, 23, 47, ?, 191Read the answer and worked solution →Find the next: 8, 27, 64, 125, ?Read the answer and worked solution →Find the next: 100, 50, 25, 12.5, ?Read the answer and worked solution →Find the next: A, C, E, G, ?Read the answer and worked solution →Find the missing: B, D, F, H, ?, LRead the answer and worked solution →Find the next: AZ, BY, CX, DW, ?Read the answer and worked solution →Find the next: ACE, BDF, CEG, ?Read the answer and worked solution →In the series Z Y X W V U T S, what is the 5th letter from the right?Read the answer and worked solution →

Worked practice questions

Find the next number: 2, 6, 12, 20, 30, ?

  1. 40
  2. 36
  3. 42
  4. 44
Show answer and solution

Correct answer: C. 42

**Differences:** 4, 6, 8, 10 (increasing by 2). Next difference = 12. So 30 + 12 = 42. Equivalent: n(n+1) for n=1,2,3,... giving 2, 6, 12, 20, 30, 42.

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Find the next number: 1, 4, 9, 16, 25, ?

  1. 49
  2. 36
  3. 32
  4. 30
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Correct answer: B. 36

Series of perfect squares: 1², 2², 3², 4², 5². Next = 6² = 36.

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Find the next: 3, 7, 15, 31, 63, ?

  1. 125
  2. 99
  3. 127
  4. 95
Show answer and solution

Correct answer: C. 127

Each term is 2 × previous + 1: 3 → 7 (2×3+1), 7 → 15 (2×7+1), 15 → 31, 31 → 63, 63 → 127. Or 2ⁿ⁺¹ - 1.

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How to practise

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