# Wrong number series questions for IBPS PO PDF

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## Wrong number series questions for IBPS PO PDF

Download Top-15 Banking Exams Wrong number series questions PDF. Banking Exams Wrong number series questions based on asked questions in previous exam papers very important for the Banking  exams.

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Instructions

Find the next term in the series.

Question 1: 442, 378, 346, 330, 322

a) 320

b) 318

c) 310

d) 314

e) 316

Question 2: 20,40,61,84,111

a) 138

b) 146

c) 136

d) 144

e) None of these

Question 3: 1,7,17,31,49,71

a) 91

b) 86

c) 97

d) 87

e) None of these

Question 4: 2,4,8,14,22,32

a) 46

b) 40

c) 42

d) 44

e) None of these

Question 5: 2,12,36,80,150

a) 252

b) 246

c) 254

d) 244

e) None of these

Instructions

In the following number series, only one number is ‘‘wrong’’. Find out the ‘’wrong’’ number.

Question 6: 13, 15, 17, 18, 21, 23

a) 17

b) 15

c) 21

d) 18

e) None of these

Question 7: 3.5, 4, 14, 56, 782, 43904

a) 14

b) 56

c) 782

d) 43904

e) None of these

Question 8: 128, 640, 981, 1199, 1324, 1388

a) 640

b) 1199

c) 1324

d) 1388

e) None of these

Question 9: 12, 114, 600, 2428, 7272, 14550

a) 2428

b) 7272

c) 600

d) 114

e) None of these

Question 10: 828, 424, 220, 116, 64, 33

a) 220

b) 64

c) 33

d) 116

e) None of these

Instructions

In each of these questions, a number series is given. Only one number is wrong in each series. You have to find out the wrong number

Question 11: 10, 15, 24, 35, 54, 75, 100

a) 35

b) 75

c) 24

d) 15

e) 54

Question 12: 1 3 4 7 11 18 27 47

a) 4

b) 11

c) 18

d) 7

e) 27

Question 13: 3, 2, 3, 6, 12, 37.5, 115.5

a) 37.5

b) 3

c) 6

d) 2

e) 12

Question 14: 2, 8, 32, 148, 765, 4626, 32431

a) 765

b) 148

c) 8

d) 32

e) 4626

Question 15: 2 3 11 38 102 229 443

a) 11

b) 229

c) 102

d) 38

e) 3

In the given series the sum of two consecutive terms are in GP
442-378 = 64
378-346 = 32
346-330 = 16
330-322 = 8
322-x = 4
x = 318

20 = 19+1
40 = (19*2)+2
61 = (19*3)+4
84 = (19*4)+8
111 = (19*5)+16
Next term = (19*6)+32 = 146

1 =$2(1)^2-1$
7 =$2(2)^2-1$
17 =$2(3)^2-1$
31 =$2(4)^2-1$
49 =$2(5)^2-1$
71 =$2(6)^2-1$
Next terms =$2(7)^2-1 = 97$

4-2 = 2
8-4 = 4
14-8 = 6
22-14 = 8
32-22 = 10
Next term = 32+12 = 44

2 =$n^3+n^2$
12 =$2^3+2^2$
36 =$3^3+3^2$
80 =$4^3+4^2$
150 =$5^3+5^2$
Next term =$6^3+6^2 = 252$

The difference between any two consecutive numbers is 2. So, the number that is wrong in the series is 18.

The correct series is 13 15 17 19 21 23.

$3.5 \times 4 = 14$

$4 \times 14 = 56$

$14 \times 56 = 784$

$56 \times 784 = 43904$

The odd one out in the given sequence is 782.

Let us find the difference between consecutive terms of the series.

The terms are 128, 640, 981, 1199, 1324 and 1388
And the difference between consecutive terms is 512, 341, 218, 125, 64

We notice that if 981 is replaced by 983, the difference in the terms will be perfect cubes i.e 512, 343, 216, 125 and 64.
Hence, the number which is wrong in the series is 983

2428. All others are divisible by 3.

424 = 828/2 + 10

220 = 424/2 + 8

116 = 220/2 + 6

The next number should be 116/2 + 4 = 62

So, 64 is the wrong number in the series.

Let us find the difference between consecutive terms of the series.
The numbers in the series are 10, 15, 24, 35, 54, 75, 100
And their differences are 5, 9, 11, 19, 21, 25. There is no obvious pattern in this.

But if we replace 35 with 37, we see the following numbers 10, 15, 24, 35, 54, 75, 100
And the differences are 5, 9, 13, 17, 21, 25 which is a symmetric pattern.

Hence, the term which is wrong in the series is 35

The given series is a Fibonacci series with each term equal to the sum of the previous two terms.

For example, 1 + 3 = 4
3 + 4 = 7
4 + 7 = 11
7 + 11 = 18
11 + 18 = 29
18 + 29 = 47

Hence, the incorrect term in the series is 27 (it should have been 29)

The numbers are based on the following pattern.

3*0.5 + 0.5 = 2
2*1 + 1 = 3
3*1.5 + 1.5 = 6
6*2 + 2 = 14
14*2.5 + 2.5 = 37.5
37.5*3 + 3 = 115.5

In the series given, we notice that 14 is replaced by 12 and hence the wrong term in the series is 12

$32431 = 7 \times 4626 + 7^2$
$4626 = 6 \times 765 + 6^2$
$765 = 5 \times 148 + 5^2$
Following the same pattern,
$148 = 4 \times 33 + 4^2$
$33 = 3 \times 8 + 3^2$
$8 = 2 \times 2 + 2^2$

32 is the wrong number here.

$3-2 = 1 = 1^3$
$11-3 = 8 = 2^3$
$38 -11 = 27 = 3^3$
$102-38 = 64 = 4^3$
$229-102 = 127 \neq 5^3$
But $227-102 = 125 = 5^3$
$443-227 = 216 = 6^3$