Number Series Questions for Bank Exams

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

(c) 6

(d) -2

(e) 38

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

(a) 54.5

(b) 18

(c) 5

(d) 9

(e) 164.5

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

(a) 102

(b) 218

(c) 350

(d) 500

(e) 422

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

(a) 72

(b) 42

(c) 30

(d) 6

(e) 52

Q5.  125, 164, 284, 484, 764, 1124

(a) 120

(b) 125

(c) 116

(d) 108

(e) 136

 

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

(a) 384

(b) 514

(c) 394

(d) 375

(e) 434

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

(a) 279

(b) 250

(c) 295

(d) 456

(e) 799

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

(a) 22

(b) 28

(c) 56

(d) 16

(e) 40

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

(a) 57

(b) 8

(c) 6996

(d) 1165

(e) 6

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

(a) 15

(b) 75

(c) 296

(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

(c)82

(d)90

(e)68

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

(a)39

(b)31

(c)29

(d)27

(e)33

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

(a)154

(b)126

(c)86

(d)112

(e)72

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

(a)72

(b)84

(c)36

(d)60

(e)48

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

(a)12

(b)24

(c)15

(d)18

(e)21

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

(a)34.5

(b)32

(c)30.5

(d)31.5

(e)33

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

(a)210

(b)208

(c)206

(d)204

(e)202

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

(a)38

(b)28

(c)36

(d)54

(e)27

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

(a)39

(b)58

(c)62

(d)45

(e)57

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

(a)302

(b)264

(c)292

(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

(c) 185

(d) 190

(e) 195

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

(a) 2

(b) 4

(c) 3

(d) 5

(e) 8

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

(a) 81

(b) 86

(c) 87

(d) 93

(e) 103

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

(a) 3

(b) 5

(c) 2

(d) 11

(e) 17

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

(a) 132

(b) 90

(c) 73

(d) 93

(e) 87

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

(a) 615

(b) 599

(c) 587

(d) 601  

(e) 593

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

(a) 17

(b) 14

(c) 18

(d) 16

(e) 25

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

(a) 112

(b) 104

(c) 106

(d) 114

(e) 100

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

(a) 1337

(b) 1327

(c) 1317

(d) 1307

(e) 1347

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

(a) 51

(b) 41

(c) 61

(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

(c) 244

(d) 292

(e) 332

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

(a) 15

(b) 31

(c) 127

(d) 512  

(e) 63

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

(a) 613

(b) 805

(c) 734

(d) 563

(e) 521

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

(a) 630

(b) 149

(c) 325

(d) 457

(e) 179

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

(a) 430

(b) 314

(c) 674

(d) 366

(e) 312

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

(a) 21

(b) 105

(c) 2500

(d) 420

(e) 3.5

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

(a) 1796

(b) 2166

(c) 2085

(d) 2240

(e) 1964

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

(a) 35

(b) 244

(c) 478

(d) 17

(e) 66

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

(a) 394

(b) 478

(c) 202

(d) 322

(e) 258

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

(a) 611

(b) 670

(c) 628

(d) 730

(e) 596

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

(a) 130

(b) 337

(c) 301

(d) 160

(e) 176

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

(a) 821

(b) 940

(c) 744

(d) 722

(e) 876

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

(a) 113

(b) 566

(c) 3396

(d) 3

(e) 4

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

(a) 474

(b) 990

(c) 448

(d) 444

(e) 613

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

(a) 125

(b) 343

(c) 1331

(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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