**SSC CHSL Topic Wise Study Material – General Intelligence – Number Series**

Contents

SSC CHSL Study MaterialSSC CHSL Previous PapersSSC CHSL Practice Workbook

A well arranged order of number placed in a special group is called series.

In number series, the numbers are arranged in a particular pattern based on some mathematical or logical operations.

These terms follow a certain pattern throughout the series. The candidate is required to study the given series, identify the pattern followed in the series.

The pattern of number series is based on following

- Square and square roots of a number
- Cube and cube roots of a number
- Arithmetic operations like, addition, subtraction, division and multiplication
- Prime number
- Even and odd numbers
- A combination of above relations

Number series consists of two types

**1. Find Out the Next Number** In this type of questions, a series of numbers are given and the candidates are asked to find out the next number of the series with the help of predefined pattern.

**Example 23, 24, 27, 28, 31, 32 ,? SSC(10+2)2012**

(a) 30

(b) 33

(c) 29

(d) 35

**Answer:**

**Example 17, 19, 23, 29, ? ssc (10+2)2012**

(a) 33

(b) 35

(c) 31

(d) 39

**Answer:**

(c) Series are increasing in prime number sequence. Hence, 31 will come after 29.

**2. Find Out the Wrong Number** In this type of questions, a series of numbers are given and the candidates are asked to find out the number which does not follow the pattern of series.

**Example Find the wrong number in the given series. 6,14,31,64,137,280 SSC(10+2)2011**

(a) 31

(b) 64

(c) 137

(d) 280

**Answer:**

**Example Find the wrong number in the given series. 9, 14, 19, 25, 32, 40 SSC (10+2) 2011**

(a) 14

(b) 25

(c) 32

(d) 9

**Answer:**

**Essential Points**

To solve number series questions, following key points should be kept in mind

- Candidates should know about the squares (1 to 20 numbers), cubes (1 to 13 numbers) and prime numbers.
- If the numbers of the given series increase rapidly, then multiplication is in action there.
- If the numbers of the given series decrease rapidly, then definitely division are in action there.
- If the number series increase rapidly and then it decreases rapidly, then multiplication and division are in action there.
- If the numbers of the given series are increasing equally, then definitely addition is taking place there.
- If the numbers of the given series decreases equally, then definitely subtraction is taking place there.

**Reference Corner**

**1. A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.3,12,48,? SSC (10 + 2) 2017**

(a) 96

(b) 184

(c) 192

(d) 38

**Answer:**

**Directions (Q.Nos. 2 and 3) A series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series, ssc (10+2) 2015**

**2.361,?, 169, 121, 49, 25**

(a) 196

(b) 324

(c) 256

(d) 289

**Answer:**

**3.1,1,2,3,5,?, 13,21**

(a)8

(b)6

(c)7

(d)9

**Answer:**

**Directions (Q. Nos. 4 and 5) Choose the correct alternative from the given ones that will complete the series**

**4. 1,6,13,22,33,? SSC (10 + 2) 2014**

(a) 46

(b) 44

(c) 47

(d) 43

**Answer:**

**5. 1, 8, 17, 30, ?, 76 SSC (10 + 2)2014**

(a) 59

(b) 69

(c) 39

(d) 49

**Answer:**

**Directions (Q. Nos. 6-8) A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.**

**6. 68, 81, 96, ?, 132 SSC (10 + 2) 2014**

(a) 105

(b) 110

(c) 113

(d) 130

**Answer:**

**7. 121, 253, 374, 495, ? SSC (10 + 2) 2014**

(a) 565

(b) 523

(c) 5116

(d) 5102

**Answer:**

(c)

**8. 4, 11, 30, 67, 128 ? SSC (10 + 2) 2013**

(a) 219

(b) 228

(c) 231

(d) 237

**Answer:**

(a)

**Practice Exercise**

**Directions (Q. NOS. 1 -15) In each of the following questions, a number series is given with one term missing. Choose the correct alternative that will continue the same pattern and replace the question mark (?) in the given series.**

**1. 10, 100, 200, 310, ? **

(a) 400

(b) 430

(c) 410

(d) 420

**2. 1, 4, 10, 22, 46, ? **

(a) 64

(b) 94

(c) 86

(d)122

**3. 6, 13, 25, 51, 101, ? **

(a) 201

(b) 202

(c) 203

(d) 205

**4. 8, 28, 116, 584, ? **

(a) 1752

(b) 3502

(c) 3504

(d) 3508

**5. 1, 2, 6, 7, 21, 22, 66, 67, ?**

(a) 70

(b) 134

(c) 201

(d) 301

**6. 48, 24, 96, 48, 192, ? **

(a) 76

(b) 90

(c) 96

(d) 98

**7. 6, 13, 28, 59, ? **

(a) 111

(b) 113

(c) 114

(d) 122

**8.3, 7, 23, 95, ? **

(a) 62

(b) 128

(c) 479

(d) 575

**9. 2, 3, 8, 27, 112, ? **

(a) 226

(b) 339

(c) 452

(d) 565

**10. 15, 39, 74, 122, ?, 265 SSC (10 + 2) 2012**

(a) 151

(b) 165

(c) 171

(d) 185

**11. 6, 11, 21, 26, 36, ?, 51 SSC (10 + 2) 2011**

(a) 41

(b) 39

(c) 47

(d) 48

**12. 24, 29, 39, ?, 74 SSC (10 + 2) 2011**

(a) 49

(b) 54

(c) 44

(d)50

**13. 6, 20, 8, 14, 10, 8, 12, ? SSC (10 +2) 2010**

(a) 14

(b) 2

(c) 4

(d) 10

**14. 36, 34, 30, 28, 24, ? SSC (10 + 2) 2010**

(a) 20

(b) 22

(c) 23

(d) 26

**15. 1, 4, 9, 16, 25, ?, 49 SSC (10 + 2) 2010**

(a) 27

(b) 36

(c) 64

(d) 81

**Directions (Q. NOS. 16-20) In each of the following questions, one in the number series is wrong. Find out the wrong.**

**16. 5, 27, 61,122,213,340,509 **

(a) 27

(b) 61

(c) 122

(d) 509

**17. 121, 143, 165,186,209 **

(a) 143

(b) 165

(c) 186

(d) 209

**18. 4, 10, 22, 46, 96, 190, 382 **

(a) 4

(b) 10

(c) 96

(d) 382

**19. 125, 126, 124, 127, 123, 129**

(a) 126

(b) 124

(c) 123

(d) 129

**20. 7, 11, 18, 35, 67, 131, 259**

(a) 131

(b) 35

(c) 259

(d) None of the above

**Answers**

**Hints & Solutions**

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