Reasoning Chapters

1. NUMBER AND LETTER SERIES2. ALPHANUMERIC SERIES3. MISSING NUMBER4. ANALOGY SIMILARTY5. CLASSIFICATION6. DIRECTION 7. BLOOD RELATION8. SEATING ARRANGEMENT9. PUZZLE10. ORDER AND RANKING11. SYLLOGISM12. CLOCK13. CALENDER14. WORD FORMATION15. DICE16. CUBE AND CUBOID17. MIRROR AND WATER IMAGE18. VENN DIAGRAM19. STATEMENT AND ASSUMPTION

Missing Number in Reasoning

Missing Number questions test your ability to identify patterns in numbers, often appearing in matrix, triangle, or series formats. These are common in exams like SSC, HSSC, Railway, and Bank exams.

What is a Missing Number Question?

It involves a sequence, grid, or pattern in which a number is missing. You must find the missing number by identifying the mathematical pattern or logic used.

Common Types:

  • Matrix-based missing number
  • Number triangle or pyramid
  • Arithmetic/Geometric progressions
  • Alphabet-number conversion
  • Logic-based sequences

Example:

Q: 2, 4, 6, ?, 10
Ans: 8 (Pattern: +2)

30+ Previous Year Questions with Solutions

  1. SSC CGL 2020: 5, 10, 20, 40, ?
    Ans: 80 (×2 pattern)
  2. SSC CHSL 2019: 81, 27, 9, ?, 1
    Ans: 3 (÷3 pattern)
  3. HSSC Clerk 2018: 6, 11, 21, 36, ?
    Ans: 56 (Pattern: +5, +10, +15, +20)
  4. RRB NTPC 2020: 2, 3, 5, 8, ?, 21
    Ans: 13 (Fibonacci Pattern)
  5. SSC GD 2019: 1, 4, 9, ?, 25
    Ans: 16 (Perfect squares)
  6. SSC JE 2016: 2, 4, 8, 16, ?, 64
    Ans: 32 (×2 pattern)
  7. SSC MTS 2021: 45, 40, 35, ?, 25
    Ans: 30 (-5 pattern)
  8. HSSC JE 2019: 3, 6, 18, 72, ?
    Ans: 360 (×2, ×3, ×4, ×5)
  9. RRB ALP 2018: 2, 5, 10, 17, ?
    Ans: 26 (+3, +5, +7, +9)
  10. SSC CHSL 2022: 100, 96, 88, 76, ?
    Ans: 60 (-4, -8, -12, -16)
  11. SSC CGL 2021: ?, 7, 26, 63, 124
    Ans: 1 (1³, 2³+1, 3³-1, 4³-1, 5³-1)
  12. RRB NTPC 2016: 13, 17, 19, 23, ?
    Ans: 29 (Prime Numbers)
  13. SSC JE 2020: 3, 12, 27, 48, ?
    Ans: 75 (+9, +15, +21, +27)
  14. SSC MTS 2019: 4, 16, 36, ?, 100
    Ans: 64 (Perfect Squares)
  15. SSC GD 2021: 2, 5, 10, 17, ?, 37
    Ans: 26 (+3, +5, +7, +9, +11)
  16. HSSC Group D 2018: 7, 14, ?, 56, 112
    Ans: 28 (×2 pattern)
  17. SSC CHSL 2015: 9, 18, 36, ?, 144
    Ans: 72 (×2 pattern)
  18. SSC CGL 2017: 2, 4, 8, 16, ?, 64
    Ans: 32 (×2)
  19. RRB ALP 2019: 2, 9, 28, 65, ?
    Ans: 126 (Pattern: n³ + 1)
  20. SSC JE 2022: 10, 20, 40, ?, 160
    Ans: 80 (×2)
  21. SSC CGL 2023: 11, 13, 17, 19, ?
    Ans: 23 (Odd primes)
  22. SSC CHSL 2023: 1, 4, 9, 16, ?
    Ans: 25 (n² pattern)
  23. SSC MTS 2022: 27, 64, ?, 216
    Ans: 125 (Cubes: 3³, 4³, 5³, 6³)
  24. RRB Group D 2022: 15, 30, 45, ?, 75
    Ans: 60 (+15)

Tips & Tricks

  • Check common patterns: squares, cubes, +n, -n, ×n, ÷n
  • Look for Fibonacci or alternating sequences
  • Try reverse logic when forward pattern fails
  • Watch for matrix or row-column operations
  • Practice regularly to boost speed
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