What is a number series in bank exams?

A number series is a sequence of numbers arranged according to a specific pattern. Candidates need to identify the pattern to find missing numbers or the next number.

How many number series questions are typically asked in bank exams?

The number varies, but typically 3-5 questions are included in the Quantitative Aptitude section of most bank exams.

What are the types of number series questions?

Types include arithmetic, geometric, square/cube series, Fibonacci series, mixed series and pattern-based series.

How can I improve my speed in solving number series questions?

Practice regularly, identify common patterns quickly and solve mock tests under timed conditions.

Why is number series important in bank exams?

Number series questions are common in the Quantitative Aptitude section and test logical thinking and numerical ability. Solving them efficiently can boost overall exam scores.

Number Series Questions for Bank Exams

Table of Contents

Number series is an important topic in bank exams and it is widely asked under the Quantitative Aptitude section. This topic evaluates a candidate’s logical thinking, numerical ability and problem-solving speed. Understanding the fundamentals and strategies for solving number series questions effectively is essential for success in exams like SBI Clerk, IBPS PO, RBI Assistant and other banking recruitment tests.

Number Series for Bank Exams

A number series is a sequence of numbers arranged in a particular order based on a specific pattern. The task is to find the logic behind the pattern and predict the next number(s), find the missing number(s) or find the wrong number in the series. This type of question tests how well candidates can identify patterns and apply mathematical rules quickly.

Types of Number Series Questions

Arithmetic Series: In this series, a constant number is added or subtracted to each term to produce the next term. Example: 5, 10, 15, 20, ? (Pattern: Adding 5 each time)
Geometric Series: Each term in the series is multiplied or divided by a constant number to get the next term. Example: 3, 6, 12, 24, ? (Pattern: Multiplying by 2 each time)
Square/Cube Series: This involves numbers that are squares or cubes of consecutive integers. Example: 1, 8, 27, 64, ? (Pattern: Cubes of 1, 2, 3, 4)
Fibonacci Series: Each number is the sum of the two preceding numbers. Example: 0, 1, 1, 2, 3, 5, 8, ? (Pattern: Adding the last two terms)
Mixed Series: These are complex series where a combination of different operations or alternating patterns is used. Example: 2, 4, 6, 11, 14, 20, ? (Pattern: Alternating addition and multiplication)
Pattern-Based Series: Series based on a defined rule involving patterns such as alternate operations, skipping numbers, etc. Example: 3, 7, 15, 31, ? (Pattern: Doubling the previous term and subtracting 1)

Number Series Questions for Bank Exams

Directions (1 – 10): In each of these questions a number series is given. In each series only one number is wrong. Find out the wrong number.

Q1. 15, 22, 6, 30, – 2, 38, -10

(a) 15

(b) 22

(d) -2

(e) 38

Q2. 18, 5, 9, 9.5, 23, 54.5, 164.5

(a) 54.5

(b) 18

(d) 9

(e) 164.5

Q3. 102, 158, 218, 282, 350, 422, 500

(a) 102

(b) 218

(d) 500

(e) 422

Q4. 72, 52, 42, 30, 20, 12, 6

(a) 72

(b) 42

(d) 6

(e) 52

Q5. 125, 164, 284, 484, 764, 1124

(a) 120

(b) 125

(d) 108

(e) 136

Q6. 375, 384, 394, 410, 434, 468, 514

(a) 384

(b) 514

(d) 375

(e) 434

Q7. 248, 250, 279, 295, 420, 456, 799.

(a) 279

(b) 250

(d) 456

(e) 799

Q8. 16, 22, 28, 40, 56, 76, 100

(a) 22

(b) 28

(d) 16

(e) 40

Q9. 6, 8, 18, 57, 232, 1165, 6996

(a) 57

(b) 8

(d) 1165

(e) 6

Q10. 15, 14, 26, 75, 296, 1485, 8844

(a) 15

(b) 75

(d) 26

(e) 1485

Directions (11 – 20): In each of these questions a number series is given. Find what comes at the place of question (?) mark.

Q11. 11, 13, 17, 25, 41, ?

(a)73

(b)79

(d)90

(e)68

Q12. 21, ?, 46, 66, 91, 121

(a)39

(b)31

(d)27

(e)33

Q13. 3, 6, 14, 38, ?, 206

(a)154

(b)126

(d)112

(e)72

Q14. 2, 12, ?, 240, 720, 1440

(a)72

(b)84

(d)60

(e)48

Q15. 3, 6, ?, 42, 123, 366

(a)12

(b)24

(d)18

(e)21

Q16. 11, 16.5, 22, 27.5, ?, 38.5

(a)34.5

(b)32

(d)31.5

(e)33

Q17. 390, 300, 244, 214, ?, 200

(a)210

(b)208

(d)204

(e)202

Q18. ?, 45, 36, 43, 34, 41

(a)38

(b)28

(d)54

(e)27

Q19. 7, 25, ?, 69, 99, 137

(a)39

(b)58

(d)45

(e)57

Q20. 761, 592, 448, 327, ?, 146

(a)302

(b)264

(d)276

(e)227

Directions (21-30): What will come in place of question (?) mark in the following number series?

Q21. 25, 33, 46, 69, 112, ?

(a) 175

(b) 180

(d) 190

(e) 195

Q22. ? , 5, 12, 39, 160, 805

(a) 2

(b) 4

(d) 5

(e) 8

Q23. 11, 24, 41, 62, ?, 116

(a) 81

(b) 86

(d) 93

(e) 103

Q24. 122, 114, 98, 66, ?, -126

(a) 3

(b) 5

(d) 11

(e) 17

Q25. 56, 72, 90, 110, ?, 156

(a) 132

(b) 90

(d) 93

(e) 87

Q26. 567, 571, ? , 623, 687, 787

(a) 615

(b) 599

(d) 601

(e) 593

Q27. 167, 118, 76, 42, ?, -4

(a) 17

(b) 14

(d) 16

(e) 25

Q28. ?, 120, 134, 160, 204, 272

(a) 112

(b) 104

(d) 114

(e) 100

Q29. 5, ? , 2067, 2411, 2537, 2565

(a) 1337

(b) 1327

(d) 1307

(e) 1347

Q30. 427, ? , 366, 73.2, 292.8, 97.6

(a) 51

(b) 41

(d) 71

(e) 31

Directions (31 -45): In each of these questions a number series is given. In each series, only one number is wrong. Find out the wrong number.

Q31. 404, 388, 366, 332, 292, 244, 188

(a) 188

(b) 366

(d) 292

(e) 332

Q32. 512, 255, 127, 63, 31, 15, 7

(a) 15

(b) 31

(d) 512

(e) 63

Q33. 521, 563, 613, 670, 734, 805, 883

(a) 613

(b) 805

(d) 563

(e) 521

Q34. 137, 149, 179, 235, 325, 457, 630

(a) 630

(b) 149

(d) 457

(e) 179

Q35. 312, 314, 330, 366, 430, 530, 674

(a) 430

(b) 314

(d) 366

(e) 312

Q36. 0.5, 3.5, 21, 105, 420, 1260, 2500

(a) 21

(b) 105

(d) 420

(e) 3.5

Q37.2249, 2240, 2215, 2166, 2085, 1964, 1796

(a) 1796

(b) 2166

(d) 2240

(e) 1964

Q38. 17, 35, 66, 126, 244, 478, 944

(a) 35

(b) 244

(d) 17

(e) 66

Q39. 114, 154, 202, 258, 322, 394, 478

(a) 394

(b) 478

(d) 322

(e) 258

Q40. 596, 611, 628, 647, 670, 699, 730

(a) 611

(b) 670

(d) 730

(e) 596

Q41. 130, 160, 176,301, 337, 680, 744

(a) 130

(b) 337

(d) 160

(e) 176

Q42. 711, 722, 744, 777, 821, 876, 940

(a) 821

(b) 940

(d) 722

(e) 876

Q43. 3, 4, 9, 28, 113, 566, 3396

(a) 113

(b) 566

(d) 3

(e) 4

Q44. 444, 448, 474, 489, 613, 648, 990

(a) 474

(b) 990

(d) 444

(e) 613

Q45. 125, 343, 81, 1331, 169, 3375, 289

(a) 125

(b) 343

(d) 289

(e) 81

Tips for Solving Number Series Questions

Observe Differences: Check the difference between consecutive terms to see if it follows an arithmetic or increasing/decreasing pattern.
Look for Multiplication or Division: If differences don’t show a pattern, try multiplication or division between terms.
Check for Squares and Cubes: Identify if the series consists of perfect squares, cubes, or a combination.
Alternate Patterns: Verify if there are two or more sub-patterns alternating throughout the series.
Mixed Series: For complex series, consider the possibility of mixed patterns or sequences derived from known series like Fibonacci.
Practice Time Management: Spend a reasonable amount of time on each question. If a pattern isn’t clear within 30-40 seconds, move on and return later if time permits.

Solutions:

S1. Ans(a)

Sol:

Pattern of series

Wrong number = 15

14+8=22

22-16=6

6+24=30

30 -32= -2

-2+40 =38

38-48 = -10

S2. Ans (a)

Sol. Pattern of series

Wrong number = 54.5

18×0.5-4=5

5×1+4=9

9×1.5-4=9.5

9.5×2+4=23

23×2.5-4=53.5

53.5×3+4=164.5

S3. Ans (d)

Sol. Pattern of series

Wrong number = 500

102+56=158

158+60=218

218+64=282

282+68=350

350+72=422

422+76=498

S4. Ans (e)

Sol. Pattern of series

Wrong number = 52

8×9=72

7×8=56

6×7=42

5×6=30

4×5=20

3×4=12

2×3=6

S5. Ans. (b)

Sol. Pattern of series

Wrong number = 125

124+40×1=164

164+40×3=284

284+40×5=484

484+40×7=764

764+40×9=1124

S6. Ans.(d)

Sol. Wrong number = 375.

there will be 378 in place of 375.

S7. Ans.(b)

Sol. Wrong number = 250.

there will be 252 in place of 250.

S8. Ans(a)

Sol.

Wrong number = 22

Pattern of series –

16+4=20

20+8=28
28+12=40
40+16=56
56+20=76
76+24=100

S9. Ans(e)

Sol.

Wrong number = 6

Pattern of series –

7×1+1=8
8×2+2=18

18×3+3=57

57×4+4=232

232×5+5=1165

1165×6+6=6996

S10. Ans (e)

Sol.

Wrong number = 1485

Pattern of series –

151-1 = 14

142-2 = 26

263-3 = 75

754-4 = 296

2965-5 = 1475

1475 ×6-6=8844

S11. Ans (a)

Sol.

The pattern of the series–

11+2=13

13+4=17

17+8=25

25+16=41

41+32=73

S12. Ans (b)

Sol.

The pattern of the series–

21+10=31

31+15=46

46+20=66

66+25=91

91+30=121

S13. Ans (c)

Sol.

The pattern of the series–

3+22-1=6

6+32-1=14

14+52-1=38

38+72-1=86

86+112-1=206

S14. Ans (d)

Sol.

The pattern of the series–

2×6=12

12×5=60

60×4=240

240×3=720

720×2=1440

S15. Ans (c)

Sol.

The pattern of the series–

3×3-3=6

6×3-3=15

15×3-3=42

42×3-3=123

123×3-3=366

S16. Ans (e)

Sol.

The pattern of the series–

11+5.5=16.5

16.5+5.5=22

22+5.5=27.5

27.5+5.5=33

33+5.5=38.5

S17. Ans (e)

Sol.

The pattern of the series–

390-10×9=300

300-8×7=244

244-6×5=214

214-4×3=202

202-2×1=200

S18. Ans (a)

Sol.

The pattern of the series–

38+7=45

45-9=36

36+7=43

43-9=34

34+7=41

S19. Ans (d)

Sol.

The pattern of the series–

7 25 45 69 99 137

+18 +20 +24 +30 +38

+2 +4 +6 +8

S20. Ans (e)

Sol.

The pattern of the series–

761-132=592

592-122=448

448-112=327

327-102=227

227-92=146

S21. Ans.(e)

Sol.

S22. Ans.(b)

Sol.

S23. Ans.(c)

Sol.

Pattern of series –

S24. Ans.(c)

Sol.

Pattern of series –

S25. Ans.(a)

Sol.

Pattern of series –

S26. Ans.(c)

Sol.

S27. Ans.(b)

Sol.

S28. Ans.(a)

Sol.

S29. Ans.(a)

Sol.

Pattern is —

+(11³+1), +(9³+1), +(7³+1), +(5³+1), +(33+1),

So, 5 + (11³ + 1) = 1337

S30. Ans.(c)

Sol.

Pattern is—

÷7, ×6, ÷5, ×4, ÷3, …

So, 427 ÷ 7 = 61

S31. Ans (b)

Sol.

Pattern of series-

404-16=388

388-24=364

364-32=332

332-40=292

292-48=244

244-56=188

So, Wrong number is 366.

S32. Ans (d)

Sol.

Pattern of series-

511÷2-0.5=255

255÷2-0.5=127

127÷2-0.5=63

63÷2-0.5=31

31÷2-0.5=15

15÷2-0.5=7

So, Wrong number is 512.

S33. Ans (e)

Sol.

Pattern of series-

520 563 613 670 734 805 883

+43 +50 +57 +64 +71 +78

+7 +7 +7 +7 +7

So, Wrong number is 521.

S34. Ans (a)

Sol.

Pattern of series-

137+3×4=149

149+5×6=179

179+7×8=235

235+9×10=325

325+11×12=457

457+13×14=639

So, Wrong number is 630.

S35. Ans (e)

Sol.

Pattern of series-

310+22=314

314+42=330

330+62=366

366+82=430

430+102=530

530+122=674

So, Wrong number is 312.

S36. Ans (c)

Pattern of series-

0.5×7=3.5

3.5×6=21

21×5=105

105×4=420

420×3=1260

1260×2=2520

So, Wrong number is 2500.

S37. Ans (a)

Sol.

Pattern of series-

2249-32=2240

2240-52=2215

2215-72=2166

2166-92=2085

2085-112=1964

1964-132=1795

So, Wrong number is 1796.

S38. Ans (d)

Sol.

Pattern of series-

18.5×2-2=35

35×2-4=66

66×2-6=126

126×2-8=244

244×2-10=478

478×2-12=944

So, Wrong number is 17.

S39. Ans (b)

Sol.

Pattern of series-

114 154 202 258 322 394 474

+40 +48 +56 +64 +72 +80

+8 +8 +8 +8 +8

So, Wrong number is 478.

S40. Ans. (e)

Sol.

598 611 628 647 670 699 730

+13 +17 +19 +23 +29 +31

So, Wrong number is 596.

S41. Ans (a)

Sol.

Pattern of series-

133+33=160

160+42=176

176+53=301

301+62=337

337+73=680

680+82=744

So, Wrong number is 130.

S42. Ans (b)

Sol.

Pattern of series-

711+(11×1)=722

722+(11×2)=744

744+(11×3)=777

777+(11×4)=821

821+(11×5)=876

876+(11×6)=942

So, Wrong number is 940.

S43. Ans (c)

Sol.

Pattern of series-

3×1+1=4

4×2+1=9

9×3+1=28

28×4+1=113

113×5+1=566

566×6+1=3397

So, Wrong number is 3396.

S44. Ans (d)

Sol.

Pattern of series-

445+22-1=448

448+33-1=474

474+42-1=489

489+53-1=613

613+62-1=648

648+73-1=990

So, Wrong number is 444.

S45. Ans (a)

Sol.

Pattern of series-

52=25

73=343

92=81

113=1331

132=169

153=3375

172=289

So, Wrong number is 125.

Solutions
01	a	02	a	03	d	04	e	05	b
06	d	07	b	08	a	09	e	10	e
11	a	12	b	13	c	14	d	15	c
16	e	17	e	18	a	19	d	20	e
21	e	22	b	23	c	24	c	25	a
26	c	27	b	28	a	29	a	30	c
31	b	32	d	33	e	34	a	35	e
36	c	37	a	38	d	39	b	40	e
41	a	42	b	43	c	44	d	45	a

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