CGL — General Intelligence & Reasoning: Missing Numbers

Practice these 20 carefully selected MCQs on Missing Numbers for CGL 2026. Each question includes the correct answer and a clear explanation. Practising MCQs regularly is the best way to improve speed and accuracy.

Instructions

  • Attempt all questions without looking at answers first.
  • Time yourself: target 1 minute per question.
  • Review explanations for every wrong answer.

Q1. 2, 4, 8, 16, __?

  • A. 32
  • B. 28
  • C. 24
  • D. 64
Answer: A — Each term doubles. 16×2=32.

Q2. 1, 4, 9, 16, 25, __?

  • A. 36
  • B. 49
  • C. 30
  • D. 32
Answer: A — Perfect squares: 1,4,9,16,25,36.

Q3. 3, 6, 11, 18, 27, __?

  • A. 38
  • B. 36
  • C. 40
  • D. 42
Answer: A — Differences: 3,5,7,9,11. Next: 27+11=38.

Q4. 1, 3, 7, 13, 21, __?

  • A. 31
  • B. 29
  • C. 33
  • D. 27
Answer: A — Differences: 2,4,6,8,10. Next: 21+10=31.

Q5. 2, 6, 12, 20, 30, __?

  • A. 42
  • B. 40
  • C. 44
  • D. 36
Answer: A — Differences: 4,6,8,10,12. Next: 30+12=42.

Q6. 5, 10, 20, 40, __?

  • A. 80
  • B. 60
  • C. 100
  • D. 70
Answer: A — Multiply by 2 each time. 40×2=80.

Q7. 100, 95, 85, 70, __?

  • A. 50
  • B. 55
  • C. 65
  • D. 45
Answer: A — Differences: 5,10,15,20. Next: 70-20=50.

Q8. 0, 1, 1, 2, 3, 5, 8, __?

  • A. 13
  • B. 10
  • C. 11
  • D. 12
Answer: A — Fibonacci: each term = sum of previous two. 5+8=13.

Q9. 7, 14, 28, 56, __?

  • A. 112
  • B. 100
  • C. 84
  • D. 96
Answer: A — Doubling series. 56×2=112.

Q10. 144, 121, 100, 81, __?

  • A. 64
  • B. 72
  • C. 49
  • D. 60
Answer: A — Perfect squares decreasing: 12²,11²,10²,9²,8²=64.

Q11. 2, 5, 10, 17, 26, __?

  • A. 37
  • B. 35
  • C. 39
  • D. 33
Answer: A — Differences: 3,5,7,9,11. Next: 26+11=37.

Q12. 1, 2, 4, 7, 11, __?

  • A. 16
  • B. 15
  • C. 14
  • D. 17
Answer: A — Differences: 1,2,3,4,5. Next: 11+5=16.

Q13. 3, 9, 27, 81, __?

  • A. 243
  • B. 162
  • C. 300
  • D. 200
Answer: A — Powers of 3. 3⁵=243.

Q14. 50, 45, 39, 32, 24, __?

  • A. 15
  • B. 16
  • C. 17
  • D. 14
Answer: A — Differences: 5,6,7,8,9. Next: 24-9=15.

Q15. 1, 8, 27, 64, 125, __?

  • A. 216
  • B. 180
  • C. 200
  • D. 250
Answer: A — Perfect cubes: 1³,2³,3³,4³,5³,6³=216.

Q16. 6, 11, 21, 41, __?

  • A. 81
  • B. 71
  • C. 61
  • D. 91
Answer: A — Each term: ×2 – 1. 41×2–1=81.

Q17. 2, 3, 5, 8, 13, 21, __?

  • A. 34
  • B. 29
  • C. 31
  • D. 33
Answer: A — Each = sum of previous two (Fibonacci-like). 13+21=34.

Q18. 10, 9, 7, 4, __?

  • A. 0
  • B. 1
  • C. 2
  • D. -1
Answer: A — Differences: 1,2,3,4. Next: 4-4=0.

Q19. 4, 16, 36, 64, __?

  • A. 100
  • B. 81
  • C. 121
  • D. 144
Answer: A — Squares of even numbers: 2²,4²,6²,8²,10²=100.

Q20. 1, 5, 14, 30, 55, __?

  • A. 91
  • B. 85
  • C. 77
  • D. 100
Answer: A — Differences: 4,9,16,25,36. Next: 55+36=91.

Exam Tips for Missing Numbers

  • Regular practice of 20+ questions daily builds speed and accuracy.
  • Review your mistakes — understanding why you got it wrong is crucial.
  • Attempt this topic in full mock tests under timed conditions.