IBPS RRB Number Series | IBPS RRB 2021


IBPS RRB Number series is one of the most important topics for the RRB exam. This means that there is every chance that you would encounter questions on this section in both IBPS RRB prelims and IBPS RRB Mains. Therefore, if you want to score high and get selected, then you must pay extra attention to this particular section.  Now, it is a known fact that Number series questions are often quite confusing. This often causes candidates to waste their precious time on the particular type of question. Sometimes, they also mark the wrong answers and lose valuable marks. You can’t afford to do either of that. We would be taking a closer look at IBPS RRB number series questions and see how you can solve them with ease and speed.

Different Types of IBPS RRB Number Series Questions

Before we actually start to learn the tricks that you should follow to solve number series questions in IBPS RRB, we must first know about the very nature of the questions asked in the exam. Let us take a look at some of the important things that you should know before you start your preparation.

How Many Questions Come Every Year?

The number of questions varies from year to year. But there is no doubt that this is the most common type of questions in the numerical ability paper of the IBPS RRB exam. On an average, there are at least 6-10 questions asked from this single section. However, as said before, the number of questions varies. So, in IBPS RRB 2021, you can get more questions or fewer questions from this section.

What is the difficulty of the questions?

The difficulty of the questions also varies from year to year. In some years, they might be extremely easy to solve. In other years, they might be a bit difficult. On an average, the questions on number series are of moderate difficulty.

How much do I need to practice?

The main thing that you need to do in case of number series is spotting the connection between the numbers. This is something that needs time and practice. This is the reason why you need to put in a good deal of practice. We would recommend that you practice at least for half an hour every day or every alternate day. This should be enough to help you spot the connection between the two.

The Right Technique to Solve IBPS RRB Number Series Questions

When you have a number series question in front of you, you waste a lot of time thinking about the possible connections. This is the biggest mistake that you can do. You need to use certain tricks and special techniques that would help you spot the connections and solve the questions easily. Let us see how you can do that.

The Step by Step Guide for IBPS RRB Number Series Solution

STEP 1 – Check – The first thing that you need to do is check whether the numbers in the series are in ascending or descending order. This would help you spot the connection and tell you what you need to do to get the number asked in the question.

STEP 2- Look – The next thing that you need to do is look at the first and second numbers. In most cases, the second number is the sum, product or difference between the first number and another number. This ‘another’ number is the connection that you are looking for.

STEP 3 – Confirm – You need to look at the third and the second number and see whether the connection that you discovered holds true.

For example, let us say you are being given a series of numbers 3, 6 and 12. When you look at the first two numbers, you find that the second number (6) is the product of the first number and 2. Now, when we look at the third number, we find that it is also the product of 2 and the third number. Hence, we have a connection.

If the connection that you identified between the first and second number, doesn’t apply to the second and the third number, then you need to repeat the Step 2.

The only thing that remains is to look at the option and choose the right answer.

Let us take the case of an example and see how to use this technique

Question: Find the next number in the following sequence

34, 18,10,6, 4,?

Solution: Step 1 – Check – We find that the numbers are in the descending order. Since, they are in the descending order, we would have to subtract or divide from the first number.

Step 2 – Look – We look at the first two numbers. We see that 34 -18=16. We immediately look at the next number and see that 18-10 = 8. So what could be the possible connection?

Step 3- Confirm – To find that, we move to the next number and find that the difference is 4. So, if we look at the differences, we find that the differences are being halved with every successive number. The series looks something like this


So, according to this logic, the final number would be 4-1=3

Answer: 3

This is how you should solve questions on IBPS RRB Number Series.

Practice Questions

Question 1: Look at this series: 7, 10, 8, 11, 9, 12, … What number should come next?


  1. 7
  2. 10
  3. 12
  4. 13

Answer:  B

Question 2: Look at this series: 36, 34, 30, 28, 24, … What number should come next?


  1. 20
  2. 22
  3. 23
  4. 26

Answer: B

Question 3: Look at this series: 2, 1, (1/2), (1/4), … What number should come next?


  1. (1/3)
  2. (1/8)
  3. (2/8)
  4. (1/16)

Answer:  B

So, these were some of the things that you should know before solving IBPS RRB Number Series Questions. For more such useful articles, keep browsing our website.

Best of luck!

Team Topprnotes.