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Number Series Concepts Reasoning Ability

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Number Series Concepts Reasoning Ability

Number Series Concepts Reasoning Ability


shape Introduction

Number Series is a form of numbers in a certain sequence, where some Numbers are mistakenly put into series of numbers and some numbers is missing in that series, We need to observe first and find the accurate number to that series of Numbers.

shape Types

This type of Series are based on square of a Number which is in same order and one square number is missing in that given series.
Here we have provided some Examples:

Example 1: 441, 484, 529, 576, ?
A. 565
B. 605
c. 655
D. 625
Ans: D

Example 2: 841, ?, 2401, 3481, 4761
A. 1071
B. 1331
c. 1411
D. 1521
Ans: D

Example 3:289, 225, 169, ?, 81
A. 131
B. 119
c. 121
D. 111
Ans: C

Example 4: 121, 144, 169, ?, 225
A. 196
B. 199
c. 206
D. 211
Ans: A

Example 5: ?, 2116, 2209, 2304, 2401, 5200
A. 2099
B. 2055
c. 2025
D. 1955
Ans: C

Example 5: ?, 64, 81, 100, 121
A. 45
B. 49
c. 53
D. 57
Ans: B

This type of series are based on Cube of a number which is in the same order and one cube number is missing in that given series.
Example 1: 3375, ?, 24389, 46656, 79507
A. 10442
B. 10648
c. 11976
D. 18002
Ans: B

Example 2: 729, 6859,24389, ?, 117649, 205379
A. 58937
B. 52335
c. 55324
D. 59319
Ans: D

Example 3: 1000, 8000, 27000, 64000, ?
A. 125000
B. 156000
c. 132000
D. 163000
Ans: A

Example 4: 1331, ?, 35937, 85184, 166375
A. 10539
B. 10538
c. 10649
D. 10648
Ans: D

Example 5: 125, ?, 343, 512, 729, 1000
A. 208
B. 216
c. 224
D. 285
Ans: B
This type of Series are based on ration series, where sequence are in form of ratio in difference between the numbers.All numbers are arranged in ratio sequence order.

  • A ratio is a relationship between two numbers by division of the same kind. The ratio of a:b is written as a:b = a/b.

    Example The artio 4:9 can be represented as 4/9. so, Antecedent = 4 and consequent = 9.

    Proportion:
    The idea of proportion is that two ratios are like equal
    If a : b = c : d. then we can write a : b ::c : d.
    Here, a and d is called extremes and b and c is called mean terms.
    Example 3/15 = 1/15

    Proportion of Quantities:
    The four Quantities like a, b, c, d are proportion, then we can express it as
    a:b = c:d
    then, a : b :: c : d (a x d) = (b x c)
    Product of means = product of Extremes

    If there is given three quantities like a, d, c of same like, then we can say it’s proportion are continued.
    a : d = d : c
    Here d is called mean term and a and c are called Extremes.


  • This type of series is based on ascending or descending sequence of numbers and each continuous number is obtained by multiplying or dividing the preceding number with static number.
    Example 1: 3, ?, 45, 144, 585
    A. 18
    B. 21
    C. 23
    D. 27
    Ans: A

    Example 2: 5, 45, 405, 3645, ?
    A. 26832
    B. 28667
    C. 30551
    D. 32805
    Ans: D

    Example 3: 73205, 6655, 605, 55, ?
    A. 3
    B. 4
    C. 5
    D. 7
    Ans: C

    Example 4: 21, 84, 336, ?, 5376
    A. 1344
    B. 1262
    C. 1173
    D. 1061
    Ans: A

    Two stage Type Series
    A two Stage type series are obtain from differences of Continuous numbers themselves.
    Example 3, 9, 18, 35, 58, ….
    6, 9, 17, 23, ….

    This type of series has more than one different order are given, which has arranged in alternatively in a single series.

    Example 1: 180, 179, 160, 156, 224, ?
    A. 88
    B. 99
    C. 100
    D. 110
    Ans: B

    Example 2: 6, ?, 33, 69, 141, 285
    A. 15
    B. 18
    C. 22
    D. 31
    Ans: A

    Example 3: 4, 16, 64, 256, 1024, ?
    A. 4096
    B. 3308
    C. 4290
    D. 2896
    Ans: A