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# Number Series Practice Questions Quantitative for Banks/ IBPS/ Govt Jobs

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In this article we will list important questions about Series Number Sequence Practice Problems. Number series is an important section under quantitative or various government PSU, bank, GPS, SBI, PO clerk exams. If you are also preparing for these exams you should prepare and practice a lot in this section. It is also important to learn some basic tips and tricks to solve number series practice questions.We have further listed different type of number series sequences that are asked in exams. You should practise all of these different types of number series questions.

## General Characteristics of Number Series Questions

Number sequences questions usually consist of four to seven visible numbers along with a single missing number or, depending on the sequence’s complexity level, 2 or 3 missing numbers.

All term in the sequence meet a specific logical rule which needs to be recognised in order to find the missing terms.

## Different Types of Number Series Questions

While solving the number series you should always look for the sequence that series is going through. We have explained and given a simple question of each type of numbers in this question below you can also download them in PDF format.

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1) Arithmetic Sequences
2) Geometric Sequences
3) Exponent Sequences

a. Perfect Squares
b. Perfect Cube Sequences

4) Two-Stage Sequences
5) Mixed Sequences
6) Alternating Sequences
7) Fibonacci Sequences
8) A Combination of Sequences’ Types

## Example of Arithmetic Sequences

In arithmetic sequence questions, you will find that the differences between the numbers are obtained by adding, subtracting or performing both operations to the previous term.

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Example:

1  |  ?  |  5  |   |  9  |  11

A) 2, 6

B) 3, 7

C) 2, 8

D) 3, 6

✔️ The correct answer is B

There are two items missing. The only two visible adjacent items are 9 & 11.

The difference between them is 2.

In addition, the difference between 5 and 9 is 4 as well as between 1 and 5.

That is, in both cases the difference between the 1st and 3rd item and the 3rd and 5th item is 4.

We can conclude that the missing numbers in the series should have a difference of 2 between the items adjacent to them on either side.

The numbers 3 & 7 complete the series.

### Example Question of Geometric Sequences Number Series

Geometric sequence questions address the ascent or descent of moving numbers.

Here, each term is obtained by multiplying, dividing or using both operations, to the previous term by a specific number or order of numbers.

Example:

0  |  3/4  |  8/9  |  15/16  |  24/25  |  ?

A) 29/28

B) 33/32

C) 35/36

D) 37/38

The series in this question follows the pattern:

1-n2, n= 1/1, 1/2, 1/3, 1/4…

### Example Questions of Exponential Sequences

Exponent sequences display all terms as exponent numbers, moving in a specific order.

They can be broken down into 2 groups: 1) perfect square and 2) perfect cube sequences. Below is a breakdown of each group.

a. Perfect Squares

In perfect square sequences, all terms are perfect square numbers (x2) moving in a specific order.

Example:

What is the following number in the series?

720  |  720  |  360  |  ?  |  30  |  6

A) 180

B) 120

C) 90

D) 60

Solving tip: A good way to tackle this question would be to examine it backwards- starting from the last term, working your way up to the first term.

This tip can be useful especially in questions where you are required to find a term that is in the middle of the series.

b. Perfect Cube Sequences

In a perfect cube sequences, all terms are cubed numbers (x3), also moving in a specific order.

Example:

0  |  3/4  |  8/9  |  15/16  |  24/25  |  ?

A) 29/28

B) 33/32

C) 35/36

The correct answer is 35/36 (C)

The series in this question follows the pattern:

1-n2, n= 1/1, 1/2, 1/3, 1/4…

### 4) Two-Stage Sequences

In Two-stage sequences you will find that the differences between consecutive terms form an arithmetic or a geometric sequence. Thus the logical rule needs to be discovered.

Example:

1  |  ?  |  5  |  ?  |  9  |  11

A) 2, 6

B) 3, 7

C) 2, 8

### Number Series Mixed Sequences

Mixed sequences cover a single sequence with more than 1 arithmetic rule characterising it.

Example:

0  |  3/4  |  8/9  |  15/16  |  24/25  | ?

A) 29/28

B) 33/32

C) 35/36

D) 37/38

The series in this question follows the pattern:

1-n2, n= 1/1, 1/2, 1/3, 1/4…

### Practice Question Alternating Sequences

Here, a single sequence made of alternating terms form two independent sub-sequences and combine them.

Example:

3  |  8  |  15  |  24  |  35  |  ?

A) 42

B) 36

C) 48

D) 46

The value of the differences increases by 2 each time.

Therefore 13 (11 + 2) should be added to the last term in the series.

35 + 13 = 48

### Fibonacci Sequences

Each term known as a Fibonacci number is the sum of the 2 preceding numbers in a sequence. The simplest Fibonacci sequence is: 1, 1, 2, 3, 5, 8, etc.

Example:

Z2  |  Y4  |  X8  |  W16  |  ?

A) V32

B) S32

C) V24

D) S24

The correct answer is V32 (A)

The series in this question follows 2 sets of rules:

1) The letters decrease by -1.

2) The numbers double each time.

### A Combination of Sequences’ Types

This sample question follows both set of rules found in two-stage sequences and exponent sequences.

Example:

3  |  3  |  3  |  6  |  3  |  9  |  3  |  ?

A) 3

B) 27

C) 12

D) 6

The correct answer is 12 (C).

There are 2 ways to look at this series:

I) There are 2 inner series. each following a different rule: Odd terms- remain constant: 3. Even terms- increase by 3:

3+3=6

6+3=9, 9+3=12

II) Another point of view:

The series in this question follows 2 rules:

I) The mathematical operations between the terms change in a specific order, x, : and so forth.

II) Every two steps the number by which the terms are multiplied or divided increases by 1.

## Find out that wrong number in each series.

Q1: 2 3 10 38 172

1 . 92

2. 10

3. 38

4. 25

Sol: Option 3
Explanation: Logic is 2 × 1 + 1 = 3, 3 × 2 + 4 = 10, 10 × 3 + 9 = 39. Thus the wrong number is 40,it should be 39.

Qus 2: 35 19 11 7 5 4.5 3.5

1. 4.5

2. 5

3. 11

4. 195. 7

Sol: Option 1
Explanation: 35-19 = 16, 19-11 = 8, 11-7 = 4, 7-5 = 2, 5-4 = 1, 4-3.5 = .5 The difference is halved every time. Thus the wrong number is 4.5, it should be 4.

Question 3: What should come in place of question mark ‘?’ in the following number series?1, 3, 7, 15, 31, ?

A) 63

B)70

C) 51

D) 41

We have the terms of the given series as

⇒ 21 – 1 = 1

⇒ 22 – 1 = 3

⇒ 23 – 1 = 7

⇒ 24 – 1 = 15

⇒ 25 – 1 = 31⇒ ? = 26 – 1 = 63