Number Series Problems - Questions and Solved Examples - Quantitative Aptitude Quiz

  • Look at this series: 2, 1, (1/2), (1/4), ... What number should come next?
    A. (1/3)
    B. (1/8)
    C. (2/8)
    D. (1/16)

  • Answer: B. (1/8)
    Explanation: This is an example of division series; where each successive number is one-half of the previous number.
    4/2 = 2; 2/2 = 1; 1/2 = 1/2; (1/2)/2 = 1/4; (1/4)/2 = 1/8 and so on.

  • Look at this series: 1.5, 2.3, 3.1, 3.9, ... What number should come next?
    A. 4.2
    B. 4.4
    C. 4.7
    D. 5.1

  • Answer: C. 4.7
    Explanation: This is an example of addition series, where each successive number increases by 0.8.

    Quantitative Aptitude Made Simpler – Number Series I in Hindi (Basics and Methods, Examples, Math Tricks)



  • Look at this series: 7, 10, 8, 11, 9, 12, ... What number should come next?
    A. 7
    B. 10
    C. 12
    D. 13

  • Answer: B. 10
    Explanation: This is an example of alternating addition and subtraction series. In the first pattern, 3 is added; in the second, 2 is subtracted and so on.

  • Look at this series: 3, 4, 7, 8, 11, 12, ... What number should come next?
    A. 7
    B. 10
    C. 14
    D. 15

  • Answer: D. 15
    Explanation: This is an example of alternating addition series. In the first pattern, 1 is added; in the second, 3 is added and so on.

  • Look at this series: 31, 29, 24, 22, 17, ... What number should come next?
    A. 15
    B. 14
    C. 13
    D. 12

  • Answer: A. 15
    Explanation: This is an example of alternating subtraction series. In the first pattern, 2 is subtracted; in the second, 5 is subtracted and so on.
  • Look at this series: 14, 28, 20, 40, 32, 64, ... What number should come next?
    A. 52
    B. 56
    C. 96
    D. 128

  • Answer: B. 56
    Explanation: This is an example of alternating multiplication and subtraction series. In the first pattern, 2 is multiplied, in the second, 8 is subtracted and so on.

  • Look at this series: 22, 21, 23, 22, 24, 23, ... What number should come next?
    A. 22
    B. 24
    C. 25
    D. 26

  • Answer: C. 25
    Explanation: This is an example of alternating subtraction and addition series. In the first pattern, 1 is subtracted; in the second, 2 is added and so on.

  • Look at this series: 53, 53, 40, 40, 27, 27, ... What number should come next?
    A. 10
    B. 14
    C. 40
    D. 53

  • Answer: B. 14
    Explanation: This is an example of repetition and subtraction number series. Each number is repeated, then 13 is subtracted to arrive at the next number.

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  • Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?
    A. 14
    B. 15
    C. 21
    D. 23

  • Answer: B. 15
    Explanation: This is an example of alternative addition number series with a random number 21, interpolated as every other number. In the series, 2 is added to each number except 21, to arrive at the next number.

  • Look at this series: 8, 22, 8, 28, 8, ... What number should come next?
    A. 8
    B. 28
    C. 30
    D. 34

  • Answer: D. 34
    Explanation: This is an example of addition series with a random number 8, interpolated as every other number. In the series, 6 is added to each number except 8, to arrive at the next number.

  • Look at this series: 36, 34, 30, 28, 24, ... What number should come next?
    A. 20
    B. 22
    C. 23
    D. 26

  • Answer: B. 22
    Explanation: This is an example of Subtraction Number Series. -2 and -4 is followed.
  • Look at this series: 58, 52, 46, 40, 34, ... What number should come next?
    A. 26
    B. 28
    C. 30
    D. 32

  • Answer: B. 28
    Explanation: This is an example of simple Subtraction Number Series. -6 is followed.

  • Look at this series: 201, 202, 204, 207, ... What number should come next?
    A. 205
    B. 208
    C. 210
    D. 211

  • Answer: D. 211
    Explanation: This is an example of successive Addition Number Series. +1, +2, +3, +4 is followed.

  • Look at this series: 544, 509, 474, 439, ... What number should come next?
    A. 404
    B. 414
    C. 420
    D. 445

  • Answer: A. 404
    Explanation: This is an example of simple Subtraction Number Series. -35 is followed.

    Quantitative Aptitude Made Simpler – Number Series II in Hindi (Basics and Methods, Examples, Math Tricks)



  • Look at this series: 1,000, 200, 40, ... What number should come next?
    A. 8
    B. 10
    C. 15
    D. 20

  • Answer: A. 8
    Explanation: This is an example of Multiplication Number Series. 1000 is 5 times of 200. And 200 is 5 times of 40. Similarly, 40 is 5 times of 8.

  • Look at this series: 4, ..., 14, 40, 88, 170. What number should come next?
    A. 6
    B. 8
    C. 10
    D. 12

  • Answer: A. 6
    Explanation: Watch the Number Series (Part II) Video!

  • Look at this series: 6, 6, 7, ..., 91, 463. What number should come next?
    A. 25
    B. 33
    C. 38
    D. 43

  • Answer: A. 25
    Explanation: Watch the Number Series (Part II) Video!