# Number Series-Reasoning Questions and Answers

Number series is a form of series in which particular numbers are present in a particular order and missing numbers are to find out, nowadays number series is an important part of each and every government exams, especially in banks. It acquires a high weight. A series is solved by particular number series tricks, formulas, attitudes of a person. There are various types of series present in the exam. Series can be of many types of Numbers like Natural numbers, Whole numbers, Contagious numbers etc. Number Series-Reasoning Questions and Answers are listed below.

Here are Number Reasoning Question and Answers

1.Look at this series: 15, __, 27, 27, 39, 39, ... What number should fill the blank?

A)   51                                                         B)   49
C)   23                                                        D)   15

Explanation:In this simple addition with repetition series, each number in the series repeats itself, and then increases by 12 to arrive at the next number.

2. Find the next two numbers : 11, 14, 14, 17, 17, 20, 20,...

A. 23 23                                                    B. 23 26

C. 21 24                                                     D. 24 24

Explanation:This is a simple addition series with repetition. It adds 3 to each number to arrive at the next, which is repeated before 3 is added again.

3. 2, 3, 4, 5, 6, 4, 8,

A. 9 10                                                        B. 4 8

C. 10 4                                                        D. 9 4

Explanation: This is an alternating addition series with a random number, 4, interpolated as every third number. In the main series, 1 is added, then 2 is added, then 1, then 2, and so on.

4. (14, 272), (17, 182), __, (23, 56), (26, 20)

A. (19, 110)                                                B. (20, 150)

C. (20, 100)                                               D. (21, 462)

Explanation: (14, 272), (17, 182), __, (23, 56), (26, 20)

The given series is a mixed series. 14+3, 17+3, 20+3, 23+3, 26.
272, 182, __56, 20
=> 162 + 16, 132 + 13, 102 + 10, 72 + 7, 42 + 4.
The missing pair is (20, 100)

5. Look at this series: 8, 43, 11, 41, __, 39, 17, ... What number should fill in the blank?

A.   8                                                            B.   14
C.   43                                                          D.   44

Explanation: This is a simple alternating addition and subtraction series. The first series begins with 8 and adds 3; the second begins with 43 and subtracts 2.

6. Look at this series: 2, 1, (1/2), (1/4), ... What number should come next?

A)   (1/3)                                                   B)   (1/3)
C)   (2/8)                                                  D)   (1/16)

Explanation: This is a simple division series; each number is one-half of the previous number.In other terms to say, the number is divided by 2 successively to get the next result.

4/2 = 2,   2/2 = 1,    1/2 = 1/2,   (1/2)/2 = 1/4,   (1/4)/2 = 1/8 and so on.

7. Find the Wrong Number:  5, 8, 15, 26, 50, 98, 194

A. 15                                                            B. 26

C. 50                                                           D. 98

Explanation:Here the actual series can be represented as follows;

5*2-2, 8*2-2, 14*2-2, 26*2-2, 50*2-2, 98*2-2, 194
15 is the wrong term in the series.

8. 10, 200, 3000, 40000

A. 500000                                                B. 400000

C. 50000                                                   D. 6000000

Explanation:10, 200, 3000, 40000, __The given series is based on digit logic the first digits in all the numbers are consecutive natural numbers followed by as many number of zero as the value of the first digit by as many number. Hence, the next number in the series is 500000.

9. The given sequences of numbers will be such that every number takes after its predecessor in the same way, i.e., according to a particular pattern. Hopefuls are required to figure out the right ways in which the sequence is formed and thereafter find out the number to finish the arrangement.

1. 30, 34, 43, 59, 84, 120,?

A.169                                                           B. 148
C.153                                                           D.176

Explanation: The given pattern is:
+22, 32, +42, + 62, +72
So, missing term is 169=120 +72
2. 40, 54, 82, ?, 180 ,250

A. 142                                                          B. 124
C. 136                                                         D. 163

Explanation:The pattern is: +14, + 28, + 42, + 52, + 70
So, missing term is 82 + 42=124

10. Some of the questions asked in number series previous papers –

Directions: (1-4) In each of these questions a number series is given. In each series stand out number isn’t right. Discover the wrong number. (IBPS CWE PO/MT Exam 2012)

1. 5531, 5506, 5425, 5304, 5135, 4910, 4621

A. 5531                                                      B. 5425
C. 4621                                                      D. 5135

Explanation: The number should be 5555 in place of 5531.
-72, -92, -112, -132, -152, -172…

2. 6, 7, 9, 13, 26, 37, 69

A. 7                                                              B. 26
C. 69                                                           D. 37

Explanation: The number should be 21 in place of 26.
+1, +2, +4, +8, +16, +32

3. 1, 3, 10, 36, 152, 760, 4632

A. 3                                                                B. 36
C. 4632                                                         D. 760

Explanation:The number should be 770 In place of 760.
×1 +2, ×2 +4, ×3 +6, ×4 + 8, ×5 +10, ×6 + 12, …

4. 4, 3, 9, 34 ,96, 219, 435

A. 4                                                            B. 9
C. 34                                                          D. 435

Explanation:The series is 02+ 4, 12+2, 32+0, 62-2, 102-4, 152- 6,212 – 8…
Hence, 435 should be replaced with 433

10. 2, 4, 12, 24, 72, 142, 432

A. 432                                                          B. 12
C. 142                                                           D. 72 Explanation: There are two alternate series and in each  series, the numbers are multiplied by 6 to get the next number.