Number Series is a crucial section of Quantitative Aptitude in every competitive exam like IBPS PO, IBPS Clerk, SBI PO, SBI Clerk, RBI Grade B, RBI Assistant, and LIC Assistant. Practice is the only key to getting command over Number Series. These number series questions set will guide you through obtaining a good score in all bank exams.

SET 01

Missing Number Series

Find the number in place of question mark (?) in the following Missing number series questions given below.

Q1. Find the missing number in the given series:
200, 197, 185, 163, 130, ? [SBI PO 2019]

a.95

b.85

c. 105

d. 86

e. 84

Ans: b) 85
Explanation:
Double Difference

Q2. Find the missing number in the given series:
15, 8, 9, 15, 32, ? [SBI PO 2019]

a. 95

b. 66

c. 80.5

d. 82.5

e. 84.6

Ans: d) 82.5
Explanation:
15×0.5+0.5=8
8×1+1=9
9×1.5+1.5=15
15×2+2=32
32×2.5+2.5=82.5

Q3. Find the missing number in the given series:
5, 30, 150, 600, ? [SBI PO 2019]

a. 1200

b. 1500

c. 2400

d. 1800

e. 600

Ans: d) 1800
Explanation:
5×6=30
30×5=150
150×4=600
600×3=1800

Q4. Find the missing number in the given series:
222, 110, 54, 26, ? [SBI PO2019]

a. 10

b. 12

c. 8

d. 6

e. 14

Ans: b) 12
Explanation:
222×0.5–1=110
110×0.5–1=54
54×0.5–1=26
26×0.5–1=12

Q5. Find the missing number in the given series:
104, ?, 96, 120, 88, 128 [SBI PO 2019]

a. 112

b. 96

c. 116

d. 120

e. 92

Ans: a) 112
Explanation:
+ 8, - 16, + 24, - 32, + 40
? = 104 + 8 = 112

Q6. Find the missing number in the given series:
11, 20, 38, 74, ? [IBPS PO 2016]

a. 146

b. 154

c. 128

d. 132

e. 136

Ans: a) 146
Explanation:
+9, +18, +36, +72…
?=74 + 72 = 146

Q7. Find the missing number in the given series:
15, 21, 38, 65, 101, ? [IBPS PO 2016]

a. 124

b. 145

c. 136

d. 158

e. 162

Ans: b) 145
Explanation:
Double Difference

Q8. Find the missing number in the given series:
24, 28, 19, 35, 10, ? [IBPS PO 2016]

a. 26

b. 36

c. 16

d. 46

e. 115

Ans: d) 46
Explanation:
+2², -3², +4², -5², +6²
10+6²=46

Q9. Find the missing number in the given series:
7, 16, 45, 184, 915, ? [IBPS PO 2016]

a. 2092

b. 5496

c. 1048

d. 4038

e. 3268

Ans: b) 5496
Explanation:
×2+2, ×3−3, ×4+4, ×5−5, 6+6
915×6+6 = 5496

Q10. Find the missing number in the given series:
12, 19, 35, 59, 90, ? [IBPS PO 2016]

a. 134

b. 127

c. 132

d. 98

e. 114

Ans: b) 127
Explanation:
Double Difference

Q11. Find the missing number in the given series:
3, 5, 15, 45, 113 ? [IBPS PO 2017]

a. 190

b. 234

c. 293

d. 243

e. 208

Ans: d) 243
Explanation:
+1³+1, 2³+2, 3³+3, 4³+4, 5³+5

Q12. Find the missing number in the given series:
17, 98, 26, 98, 35, ? [IBPS PO 2017]

a. 78

b. 79

c. 80

d. 81

e. 82

Ans: c) 80
Explanation:
Alternative Seies (Detailed in the below)

Q13. Find the missing number in the given series:
3240, 540, 108, 27, ?, 4.5 [IBPS PO 2017]

a. 12

b. 7

c. 9

d. 8

e. 6

Ans: c) 9
Explanation:
÷6, ÷5, ÷4, ÷3, ÷2

Q14. Find the missing number in the given series:
7, 4.5, 5.5, 12, 49, ? [IBPS PO 2017]

a. 393

b. 378

c. 197

d. 148

e. 246

Ans: a) 393
Explanation:
×0.5+1, ×1+1, ×2+1, ×4+1, ×8+1

Q15. Find the missing number in the given series:

2, 17, 89, 359, 1079, ? [IBPS PO 2017]

a. 2159

b. 2162

c. 1080

d. 2142

e. 2079

a) Ans: 2159
Explanation:
x6+5, x5+4, x4+3, x3+2, x2+1

Wrong Number Series

In each of these questions series, a wrong number is given. Find out the wrong number that does not belong to the series.

Q1. Find the wrong number in the given series:
1, 3, 9, 31, 128, 651, 3913 [SBI PO 2018]

a.9

b.1

c. 128

d. 31

e. 3913

Ans: b) 128
Explanation:
×1+2, ×2+3, ×3+4, ×4+5, ×5+6, ×6+7

Q2. Find the wrong number in the given series:
291, 147, 75, 39, 22, 12, 7.5 [SBI PO 2018]

a. 22

b. 291

c. 147

d. 75

e. 7.5

Ans: a) 22
Explanation:
÷2+1.5, ÷2+1.5, ÷2+1.5, ÷2+1.5, ÷2+1.5,÷2+1.5

Q3. Find the wrong number in the given series:
26, 27, 34, 58, 106, 186, 306 [SBI PO 2018]

a. 26

b. 34

c. 58

d. 106

e. 27

Ans:3) 27
Explanation:
1²-1, 3²-1, 5²-1, 7²-1, 9²-1, 11²-1

Q4. Find the wrong number in the given series:
5.9, 6, 6.1, 6.4, 7.9, 18.5, 112.9 [SBI PO 2018]

a. 6

b. 5.9

c. 6.1

d. 18.5

e. 112.9

Ans: d) 18.5
Explanation:
Difference and Multiplication

Q5. Find the wrong number in the given series:
330, 80, 280, 120, 250, 130, 240 [SBI PO 2018]

a. 330

b. 130

c. 280

d. 240

e. 80

Ans: b) 130
Explanation:
Double Difference

Q6. Find the wrong number in the given series:
5, 18, 34, 54, 79, 110, 158 [SBI PO 2020]

a. 34

b. 5

c. 18

d. 54

e. 158

Ans: e) 158
Explanation:
Double Differenced

Q7. Find the wrong number in the given series:
112, 128, 108, 132, 104, 134, 100 [SBI PO 2020]

a. 112

b. 128

c. 134

d. 108

e. 100

Ans: c) 143
Explanation:
112 + 16, 128 – 20, 108 + 24, 132 – 28, 104 + 32, 136 − 36

Q8. Find the wrong number in the given series:
5, 6, 14, 45, 184, 920, 5556 [SBI PO 2020]

a. 5

b. 6

c. 14

d. 920

e. 45

Ans: d) 920
Explanation:
×1+1, ×2+2, ×3+3, ×4+4, ×5+5, ×6+6

Q9. Find the wrong number in the given series:
10, 22, 35, 50, 68, 92, 117 [SBI PO 2020]

a. 92

b. 117

c. 10

d. 22

e. 35

Ans: a) 92
Explanation:
Double Differenced

Q10. Find the wrong number in the given series:
64, 34, 36, 56, 114 , 287, 860 [SBI PO 2020]

a. 114

b. 680

c. 64

d. 36

e. 56

Ans: b) 860
Explanation:
×0.5+2, ×1+2, ×1.5+2, ×2+2, ×2.5+2, ×3+2

Q11. Find the wrong number in the given series:
4, 5.1, 7.3, 10.6, 15, 20, 27.1 [IBPS PO 2018]

a. 5.1

b. 4

c. 7.3

d. 20

e. 27.1

Ans: d) 20
Explanation:
+1.1, +2.2, +3.3, +4.4, +5.5, +6.6

Q12. Find the wrong number in the given series:
2, 3, 8, 31, 154, 924, 6460 [IBPS PO 2018]

a. 924

b. 6460

c. 154

d. 8

e. 31

Ans: a) 924
Explanation:
×2-1, ×3-1, ×4-1, ×5-1, ×6-1, ×7-1

Q13. Find the wrong number in the given series:
251, 252, 254, 227, 243, 118, 154 [IBPS PO 2018]

a. 251

b. 252

c.227

d. 243

e. 154

Ans: b) 252
Explanation:
-1³, +2², -3³, +4², -5³, +6²

Q14. Find the wrong number in the given series:
141, 156, 147, 162, 153, 165, 159 [IBPS PO 2018]

a. 165

b. 153

c. 147

d. 165

e. 159

Ans: d) 165
Explanation:
+15, -9, +15, -9, +15, -9

Q15. Find the wrong number in the given series:
2, 6, 10, 19, 36, 69, 134 [IBPS PO 2018]

a. 134

b. 69

c. 6

d. 2

e. 10

Ans: c) 6
Explanation:
Triple Difference

NEXT

In this number series question set, we provide different number series questions for all bank exams like IBPS clerk, IBPS PO, SBI clerk, SBI PO, RBI assistant based on the previous year question pattern. We also provide last year number series questions to get good command over bank exam-related number series patterns.
Practising daily a set of numbers series will help you get good command in any competitive exams as this section contributes a significant role in the quantitative aptitude portion.

Types of Number Series Questions asked in competitive exams

Number series are mainly two types. Missing number series and wrong number series. The most common patterns followed by number series are:

1. Table based Number Series:

It consists of a series in which numbers are arranged in a way that the difference of the numbers is from multiplication tables.

Example: 292, 328,382,454,544,?
Ans: 652
Explanation:
328-292 = 36
382-328 = 54
454-382 = 72
534-454 = 90
652-544 = 108
In this series 36, 54, 72, 90, 108 are from Table of 18.

2. Gape of square and cube:

It consists of a series in which numbers are arranged so that the difference of the numbers are perfect Cubes or perfect Squares.

Example: 224,232,259,323,448,?
Ans:664
Explanation:
232-224 = 8
259-232 = 27
323-259 = 64
448-323 = 125
664-448 = 216
In the above series 8,27,64,125,216 are perfect cubes.

Example: 36,40,49,65,90,?
Ans:126
Explanation:
40-36 = 4
49-40 = 9
65-49 = 16
90-65 = 25
126-90 = 36
In the above series 4,9,16,25,36 are perfect squares.

3. Double difference based number series:

To find the pattern in this series, we have to find the difference of the numbers two times.

Example: 192,223,260,305,360,?
Ans: 427
Explanation:
192  223  260  305  360  427
31    37    45    55    67
6       8     10    12
In the above series, 6,8,10,12 are the results of double difference, which are consecutive even numbers.

4. Square cube twists:

It consists of a series in which numbers are based on Square cube twits. Patterns are usually formed in the general formula n³+a, n³-a, n²+a, n²-a (Where n and a are any integers)

Example: 65,65,71,95,155,?
Ans: 275
Explanation:
65-65 = 0
71-65 = 6
95-71 = 24
155-95 = 60
275-155 = 120
In the above series 0,6,24,60,120 followed the general formula n³-a, where n=a= {1,2,3,4,5}

0 = 1³-1
6 = 2³-2
24 = 3³-3
60 = 4³-4
120 = 5³-5

Example: 17,22,32,49,75,?
Ans: 112
Explanation:
22-17 = 5
32-22 = 10
49-32 = 17
75-49 = 26
112-75 = 37
In the above series 5,10,17,26,37 followed the general formula n²+a, where n={2,3,4,5,6} and a=1

5 = 2²+1
10 = 3²+1
17 = 4²+1
26 = 5²+1
37 = 6²+1

5. Multiplication Based Number Series:

As the name of this series specifies, this type of series is formed by multiplying the previous number with integers. If the numbers are increasing or decreasing rapidly, it might have a multiplication based pattern series.

Example: 8,8,16,48,192,960,?
Ans: 5760
Explanation:
8*1 = 8
8*2 = 16
16*3 = 48
48*5 =4 192
192*5 = 960
960*6 = 5760

6. Multiplication plus addition/subtraction based series:

It consists of a series in which numbers are combined with multiplication and addition or subtraction simultaneously. It is the most commonly asked pattern in competitive exams. When the numbers increase or decrease rapidly, it might be a multiplication plus addition/subtraction based series.

Example: 4,6,15,49,201,?
Ans: 1011
Explanation:
4*1+2 = 6
6*2+3 = 15
15*3+4 = 49
49*4+5 = 201
201*5+6 = 1011

Example: 7,13,25,49,97,?
Ans: 193
Explanation:
7*2-1 = 13
13*2-1 = 25
25*2-1 = 49
49*2-1 = 97
97*2-1 = 193

7. Decimal based series:

Decimal based number series is a combination of multiplication and addition of decimal numbers. Sometimes number series itself consists of decimal numbers within it. When the numbers are increasing or decreasing rapidly, it might be a decimal-based number series.

Example: 11,6,10.5,28.75,?
Ans: 104.125
Explanation:
11*0.5+0.5 = 6
6*1.5+1.5 = 10.5
10.5*2.5+2.5 = 28.75
28.75*3.5+3.5 = 104.125

Example:
8,4.5,5.5,13,56,?
Ans: 456
Explanation:
8*0.5+0.5 = 4.5
4.5*1+1 = 5.5
5.5*2+2 = 13
13*4+4 = 56
56*8+8 = 456

8. Alternative Number Series:

In this type of series number, there are patterns in between every alternative number. It also might have a single pattern in every consecutive number. But it would be easier if we consider alternative numbers to find the pattern.

Example: 78,32,86,24,94,16,?
Ans: 102
Explanation:
78+8 = 86
32-8 = 24
86+8 = 94
24-8 = 16
94+8 = 102

9. Sum of previous Number:

In this type of series, numbers are formed by adding the previous number. If A is the first number and B is the second number, the third number will be (A+B).

Example: 11,12,23,35,58,?
Ans: 93
Explanation:
11+12 = 23
23+12 = 35
35+23 = 58
58+35 = 93

10. Percentage based number series: (New pattern)

It consists of a series in which numbers are formed by taking percentage of previous number. If A is the first number, B is the second number then B= n%of A, where n is any number from 1 to 100.

Example: 1500,150,30,9,?
Ans: 3.6
Explanation:
10% of 1500 = 150
20% of 150 = 30
30% of 30 = 9
40% of 9 = 3.6

11. Fraction based series:

It consists of a series in which numbers are arranged by multiplying some fraction with its previous number. If A is the first number and B is the second number then B= (x/y)A. Where x and y are natural numbers i.e. 1,2,3,4,5....

Example: 25,25,35,63,?
Ans: 138.6
Explanation:
25*(5/5) = 25
25*(7/5) = 35
35*(9/5) = 63
63*(11/5) = 138.6