A sequence formed out of numbers is called a number series. There are various rules which are to be detected when dealing with questions on number series. There are several series, and hence there are several questions that can arise from this series. The questions which we would see include questions like those on Perfect Square and Perfect Cube Series, Geometric Series, etc. 

We’ve come up with a detailed blog and some examples of the type of question included in Number Series for various exams, including IELTS, TOEFL, and others. These exams use quantitative aptitude to test a candidate’s capabilities. Number series and questions related to its different rules form an important part of this. Let’s check it out! But first, let’s look at the topics which come under Number Series

Various Topics included in Number Series

Like every other Mathematical topic related to quantitative aptitude, there are various topics in the number series as well. According to these topics, different exams form complicated questions for the students to solve.

Let’s look at the various topics under Number Series here –

• Perfect Square Series
• Perfect Cube Series
• Mixed Series
• Two-Stage Type Series
• Wrong Number Series
• Missing Number Series
• Decimal Fractions
• Order and Ranking
• Square and Cube Roots
• Simplification on BODMAS Rule
• Chain Rule
• Heights and Distance
• Odd Man Out Series

If your basics are strong, no matter how difficult the questions are, you can easily crack the problem.

What are some things which need to be kept in mind? 

Certain things have to be kept in mind before attempting questions from Number Series. There are various rules which are to be followed, and according to the visible trend in a number system, different operators are used. Let’s look at some of the things that need to be kept in mind before solving a number series questions. 

• In case the number series increases in a trend, addition and/or multiplication has been used. 
• Similarly, if a decreasing trend of number series is there, a division and/or subtraction operator has been used.
• Series showing a sudden surge or decline might have a square, cube, square root, or cube root in play.
• In case the number series is uneven, i.e., it increases and then decreases or decreases and then increases, it might be that there are combinations of various factors and operators used. 

‘Hit and Trial’ Method in Number Series – Is it worth the try in a real exam?

All this points to one thing – that there isn’t a defined set of formulas that would for every type of question. A ‘hit and trial’ method can be used and be kept trying for these different questions. However, in the real exam, you wouldn’t get enough time to resort to every method or trick used to solve questions of number series. So, what needs to be done?

How to get expertise on Number Series?

A lot of practice can make an important and tough topic a cakewalk, and the number series is no different. Solving different questions make you comfortable to use the concepts that you have in mind in the actual exams. Following are some of how exams with number series questions can be cracked –

• Practicing a lot of mock tests on number series
• Analyzing in detail, the solution provided after the mock test on number series.
• Keep revising the concepts which have helped in solving a complicated number series question.
• Make short notes of tips and tricks learned or discovered by you while you are practicing questions on number series. 

Some example question asked in various exams 

Find the number in place of ‘?’ in the following series

6, 8,13, ? , 40, 56

1. 23
2. 26
3. 29
4. None of these

Answer – 23

Difference between the first two numbers is 2, while the second and third number is 5. If we keep 23 in the 4th place, then the difference between 23 and 13 is 10. Thus, the difference between 2,5 and 10 is 3 and 5. The next number is 40. 40-23=17, which is 10+7, i.e., the addition of the next odd number ‘7’ to the difference between the 4th and 5th consecutive numbers.

Hence, the number is 23.

Find the number in place of ‘?’ in the following series

7, 8, 18, ?, 232, 1165

1. 56
2. 57
3. 58
4. 60

Answer – 57

See how the number series is moving ahead really rapidly! So, finding the difference between them wouldn’t suffice. It suggests that such a rapid spurt may have a multiplication factor in play. Multiplying 1 with the first number, and adding 1 to it gives the second number. Similarly, the third number is obtained by multiplying 2 with the second number and adding two after that. Therefore, the missing number would be obtained by multiplying 3 to the third number, which is 18, and adding 3 to the number. So, the solution is 18*3= 54+3 = 57. The rest of the number series follows the same pattern. Hence our answer is correct.  

Conclusion

Number series is not difficult, just a bit tricky, especially when decimal of multiplication of decimals are to be followed. Questions like these can be solved within minutes if the practice is put in to solve them. Once you have the first-hand experience in trying to solve different questions related to number series, it would be very easy for you to solve the questions on number series.