Reasoning & Numerical AbilityNumber Serieseasy

Number Series Quiz

Free practice quiz on Number Series Quiz with detailed solutions for government exam preparation.

25
Minutes
25
Marks
FREE
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About This Quiz

Number Series Quiz is a free, 25-minute, 25-mark practice quiz on AajExam rated at easy difficulty, designed to help candidates preparing for SSC, UPSC, Banking, Railway and State PSC government competitive exams sharpen their command of Number Series (Reasoning & Numerical Ability). Every question on this quiz ships with a detailed step-by-step solution so you don't just learn the right answer — you learn the reasoning and shortcuts top scorers use to crack similar questions faster on the actual exam day. Why Number Series Quiz matters in your preparation: government exam-conducting bodies repeatedly draw questions from the same chapters and the same skill-clusters across recruitment cycles. By attempting focused topic-wise quizzes like this one, you build pattern recognition — the ability to spot which formula, rule or trick applies the moment you see a question. Toppers consistently report that 5-10 quizzes on a single topic delivers more exam-day score gain than 20+ unfocused full-length mocks, because targeted drilling exposes your specific sub-topic weaknesses with surgical precision. How to use this quiz effectively: attempt it in one sitting under the 25-minute timer, without referring to notes or external resources — simulate exam-day conditions exactly. After submission, review the auto-generated analytics to see your accuracy, time per question and section-wise performance. Then go through every wrong and skipped question with the explanation, mentally tagging the underlying concept rather than just memorising the answer. Revisit this quiz after 7-10 days; your second attempt should be 15-20% faster with noticeably better accuracy. Bookmark this page and revisit weekly as we add new quizzes on related topics. AajExam quiz design principles: every quiz on the platform is curated by subject experts using the actual question formats, difficulty distributions and time pressures of the target government exams. We deliberately avoid generic "textbook" questions in favour of exam-replicating ones. Solutions are written in plain English (and Hindi where source material was bilingual), with step-by-step working for quantitative problems, grammar rules for English questions, and direct reference statements for general awareness items. Performance analytics after each attempt include accuracy, attempt rate, time spent per question, and an estimated all-India percentile so you know exactly where you stand against other candidates. This quiz is completely free to attempt. You only need a free AajExam account to track your performance across attempts, view detailed solutions and unlock the platform-wide analytics dashboard. The platform is mobile-friendly and works seamlessly on smartphones, tablets and desktops — so you can sharpen your Number Series (Reasoning & Numerical Ability) skills in any spare 15-minute window.

Number Series Quiz — Questions with Solutions

All 25 questions from this quiz with the correct answer and explanation. Attempt them yourself first, then open each solution to check your reasoning.

  1. Q1.Find the next number: 12, 15, 18, 21, ?

    • A.22
    • B.23
    • C.24
    • D.25
    Show answer

    Answer: C. 24

    This series increases by 3 each time; 21+3=24.

  2. Q2.Find the missing number: 8, 16, 24, 32, ?

    • A.36
    • B.38
    • C.40
    • D.42
    Show answer

    Answer: C. 40

    This series increases by 8 each time; 32+8=40.

  3. Q3.Find the next number: 100, 95, 90, 85, ?

    • A.75
    • B.78
    • C.80
    • D.82
    Show answer

    Answer: C. 80

    This series decreases by 5 each time; 85-5=80.

  4. Q4.Find the missing number: 3, 6, 12, 24, ?

    • A.36
    • B.42
    • C.48
    • D.54
    Show answer

    Answer: C. 48

    Each term doubles the previous one; 24*2=48.

  5. Q5.Find the next number: 2, 6, 18, 54, ?

    • A.108
    • B.144
    • C.162
    • D.180
    Show answer

    Answer: C. 162

    Each term is multiplied by 3; 54*3=162.

  6. Q6.Find the missing number: 50, 45, 41, 38, ?

    • A.34
    • B.35
    • C.36
    • D.37
    Show answer

    Answer: C. 36

    Differences decrease by 1 each time (5,4,3); the next difference is 2, so 38-2=36.

  7. Q7.Find the next number: 5, 10, 17, 26, ?

    • A.35
    • B.36
    • C.37
    • D.38
    Show answer

    Answer: C. 37

    Differences increase by odd numbers (5,7,9); 26+11=37.

  8. Q8.Find the missing number: 9, 18, 27, 36, ?

    • A.40
    • B.42
    • C.45
    • D.48
    Show answer

    Answer: C. 45

    This series increases by 9 each time; 36+9=45.

  9. Q9.Find the next number: 1, 2, 6, 24, ?

    • A.48
    • B.96
    • C.120
    • D.144
    Show answer

    Answer: C. 120

    Each term is multiplied by an increasing integer (x2,x3,x4,x5): 24*5=120.

  10. Q10.Find the missing number: 15, 30, 45, 60, ?

    • A.65
    • B.70
    • C.75
    • D.80
    Show answer

    Answer: C. 75

    This series increases by 15 each time; 60+15=75.

  11. Q11.Find the next number: 4, 9, 19, 39, ?

    • A.59
    • B.69
    • C.79
    • D.89
    Show answer

    Answer: C. 79

    Each term is doubled and 1 added: 39*2+1=79.

  12. Q12.Find the missing number: 21, 18, 15, 12, ?

    • A.8
    • B.9
    • C.10
    • D.11
    Show answer

    Answer: B. 9

    This series decreases by 3 each time; 12-3=9.

  13. Q13.Find the next number: 6, 11, 21, 41, ?

    • A.61
    • B.71
    • C.81
    • D.91
    Show answer

    Answer: C. 81

    Each term is doubled minus 1: 41*2-1=81.

  14. Q14.Find the missing number: 2, 5, 9, 14, ?

    • A.18
    • B.19
    • C.20
    • D.21
    Show answer

    Answer: C. 20

    Differences increase by 1 each time (3,4,5,6); 14+6=20.

  15. Q15.Find the next number: 30, 27, 24, 21, ?

    • A.16
    • B.17
    • C.18
    • D.19
    Show answer

    Answer: C. 18

    This series decreases by 3 each time; 21-3=18.

  16. Q16.Find the missing number: 1, 3, 7, 15, ?

    • A.23
    • B.27
    • C.31
    • D.35
    Show answer

    Answer: C. 31

    Each term is doubled and 1 added: 15*2+1=31.

  17. Q17.Find the next number: 8, 12, 18, 26, ?

    • A.34
    • B.36
    • C.38
    • D.40
    Show answer

    Answer: B. 36

    Differences increase by 2 each time (4,6,8); 26+10=36.

  18. Q18.Find the missing number: 40, 36, 32, 28, ?

    • A.22
    • B.24
    • C.26
    • D.20
    Show answer

    Answer: B. 24

    This series decreases by 4 each time; 28-4=24.

  19. Q19.Find the next number: 3, 4, 7, 11, 18, ?

    • A.25
    • B.27
    • C.29
    • D.31
    Show answer

    Answer: C. 29

    Each term is the sum of the two before it (Fibonacci-style); 11+18=29.

  20. Q20.Find the missing number: 16, 24, 32, 40, ?

    • A.44
    • B.46
    • C.48
    • D.50
    Show answer

    Answer: C. 48

    This series increases by 8 each time; 40+8=48.

  21. Q21.Find the next number: 1, 5, 13, 29, ?

    • A.45
    • B.61
    • C.54
    • D.57
    Show answer

    Answer: B. 61

    Each term is doubled and 3 added: 29*2+3=61.

  22. Q22.Find the missing number: 12, 24, 36, 48, ?

    • A.54
    • B.56
    • C.60
    • D.64
    Show answer

    Answer: C. 60

    This series increases by 12 each time; 48+12=60.

  23. Q23.Find the next number: 2, 4, 12, 48, ?

    • A.96
    • B.192
    • C.240
    • D.288
    Show answer

    Answer: C. 240

    Each term is multiplied by an increasing integer (x2,x3,x4,x5): 48*5=240.

  24. Q24.Find the missing number: 7, 14, 21, 28, ?

    • A.30
    • B.32
    • C.35
    • D.38
    Show answer

    Answer: C. 35

    This series increases by 7 each time; 28+7=35.

  25. Q25.Find the next number: 11, 22, 33, 44, ?

    • A.50
    • B.55
    • C.60
    • D.65
    Show answer

    Answer: B. 55

    This series increases by 11 each time; 44+11=55.

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Frequently Asked Questions

Is Number Series Quiz free to attempt on AajExam?

Yes. Number Series Quiz is completely free. You only need a free AajExam account to track your score, view detailed solutions and unlock cross-attempt analytics.

How long does it take to complete Number Series Quiz?

Number Series Quiz runs on a 25-minute timer in real exam-style conditions. The clock starts the moment you click Start, mirroring the time pressure of the actual exam.

Are detailed solutions provided?

Yes. Every question on Number Series Quiz ships with a complete step-by-step solution, the underlying concept, and (where applicable) shortcut tricks. You can also discuss any question with the AajExam community.

Can I attempt Number Series Quiz multiple times?

Yes. You can attempt this quiz as many times as you like. Each attempt is recorded separately so you can track improvement in score, accuracy and time-management.

Which government exams does this quiz prepare me for?

Number Series questions appear regularly in SSC CGL, CHSL, MTS, GD; IBPS PO, Clerk; SBI PO, Clerk; RRB NTPC, Group D; UPSC prelims and most State PSC exams. The specific weightage varies by exam — check the exam pattern on the corresponding AajExam exam page for details.