Number Series Questions for Competitive Exams

Competitive exams are a part of life and help us determine our future. Whether determining the direction of your career path or deciding the right college, competitive exams push us to reach an inch closer to our professional dreams. These competitive exams serve different purposes. However, most of the competitive exams consist of similar sections of questions. These common sections include a quantitative section, logical reasoning section, arithmetic reasoning, verbal and grammar section and passage reading section. The logical reasoning section is an easy section to approach if done with a calm and clear mind. The logical reasoning questions of a competitive exam also consists of number series questions. These questions appear to be simple but can be extremely tricky if your concepts are not clear. Every question in a competitive exam is important and hence understanding how to solve the number series questions for competitive examinations is a must. Let us have a look at some tips to approach such questions.

What are Number Series Questions? 

Number series questions for competitive exams are extremely important in different kinds of competitive examinations. In this type of question, there will be a series of numbers present. Along with a series of numbers, there is a blank to fill out. You are given the task of finding out the answer to the blank by figuring out the pattern between the numbers, their predecessor and their successor. It may appear to be a simple task but figuring out the logic behind the pattern is tricky. To help you understand the number series question for competitive exams, let us divide these questions into different categories, such as: 

• Series with increasing difference
• Series with a constant difference
• Series with decreasing difference
• Combination of different operations, like ‘+’ and  ‘-’ together, etc.  
• Perfect squares and cubes of numbers’ series
• Miscellaneous

These are some types of number series questions for competitive exams. Understanding the kind of category the question belongs to, will help you solve the question faster thus saving a valuable amount of time. Having established what exactly are number series questions, now let us have a look at how you should approach these questions. 

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Number Series Questions for Competitive Exams

To help you implement your understanding of Number series questions, we have compiled a list of questions. All of these questions comprise a series of questions, which are followed by a blank. Students are required to fill out the blank by identifying the pattern followed in the series. Here are some number series questions:

1. What will be the next number in this series  22, 21, 23, 22, 24, 23, …
2. What will be the next number in this series 3, 5, 7, 11, 13, _
3. What will be the next number in this series 70, 68, 64, 62, 58, _
4. What will be the next number in this series 60, 60, 57, 57, 57, 54, _
5. What will be the next number in this series 15, 18, 20, 29, 45, 70, 106, _
6. What will be the next number in this series 3, 4, 7, 8, 11, 12, _
7. What will be the next number in this series 18, 24, 16, 22, 14, 20, _
8. What will be the next number in this series 61, 59, 54, 52, 47, _
9. What will be the next number in this series 44, 09, 74, 34, _
10. What will be the next number in this series 80, 10, 70, 15, 60,_
11. What will be the next number in this series 8, 6, 9, 23, 87, _
12. Find the missing number in the series: 4, 18, ?, 100, 180, 294, 448
13. Find the missing number in the following series: 3, 5, 5, 19, 7, 41, 9, ?
14. Find the missing number in the following series: 132, 156, ?, 210, 240, 272 
15. Find the missing number in the following series:10000, 11000, 9900, 10890,?,10781
16. Identify the wrong number in the series: 3, 8, 15, 24, 34, 48, 63
17. Identify the wrong number in the series: 1, 2, 6, 15, 31, 56, 91
18. Identify the wrong number in the series: 8, 27, 125, 343, 1381
19. Identify the wrong number in the series: 15, 51, 216, 1100, ?, 46452
20. What will be the next number 53, 53, 40, 40, 27, 27, …

Number Series Questions with Solutions

Question: 5, 11, 24.2, 53.24, ?, 257.6816

Solution: The solution of the series is as follows.
5×2.2 11
11 x 2.2 = 24.2
24.2 x 2.253.24
53.24 x 2.2 117.128
117.128 x 2.2=257.6816

Hence, the correct answer is 117.128.

Question: 50, 45, 40, 35, 30, ?

Solution: The solution of the series is as follows.
50-5=45
45-5=40
40-5=35
35 5 30
30-525

Hence, the correct answer is 25.

Question: 49, 121, 169, ?, 361

Solution: The solution of the series is as follows.
7^2 = 49
11^2=121
13 2 169
17^2=289
19^2=361

Hence, the correct answer is 289.

Question 7: 12, 13, 25, 38, ?, 101, 164

Solution: The solution of the series is as follows.
12
13
25 = 12 +13
38 13+25
63= 25+ 38
101 38 +63
164 101 +63

Hence, the correct answer is 63.

Question 8: 2, 29, 4, 25, 6, 7, 8, 17

Solution: The solution of the series is as follows.
2+2=4
4+2=6
6+2=8

Similarly,

29-4 25
25 -4 = 21
21 4 17

Hence, the correct answer is 21.

Question 9: 5, 7, 21, 55, ?, 215

Solution: The solution of the series is as follows.

5+(2^2-2) = 7
7+(4^2-2) = 21
21+ (6^2-2) = 55
55+ (8^2-2) 117
117+ (10^2-2) = 215

Hence, the correct answer is 117.

Number Series Questions: Tips and Tricks

The simplest way to approach number series questions for competitive exams is to observe and comprehend the difference between the numerous terms. Here are some methods and tips you can use to solve number series questions:

• If you notice a constant difference between the different numbers, it means that the question belongs to the series with a constant degree category. 
• If you notice the difference between the numerous numbers it is either increasing or decreasing, then the question belongs to either the series with an increasing difference or the series with decreasing difference respectively. 
• In case, you are not able to spot an increasing or decreasing difference between the numbers, try to divide the 2nd term of the series with the first, the 2nd term with the 3rd term and so on. If the answer to the constant division comes as the same number, then this question belongs to the product series. 
• In case, none of the above tactics works, you can write every term of the question as to to the multiplication of 2 factors and try to spot a pattern between the terms. If you are not able to spot a pattern and the difference between the terms is decreasing or increasing at an accelerated rate, you can try for the square/cube series. 
• If the difference between the terms is decreasing or increasing in a predetermined manner, then this question may belong to the combination of different operations series. 

Also Read: Maths for Competitive Exams

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With an ample amount of practice and method study, you can quickly grasp these questions and can concentrate more on the weaker sections of your competitive exam preparation. The experts at Leverage Edu can assist you in understanding how to tackle the challenges of a competitive exam. We provide expert-led online classes for leading aptitude tests like GMAT, GRE and SATs which can help you clear your doubts and be at the top of your game during the test!