Number and Letter Series for CAT, MAT, SNAP, XAT Exams

By : Raghavendra Singh

Updated : Dec 30, 2020, 8:32

The Number and Letter Series is an essential mathematical and logical reasoning topic in various exams. The questions test the analytical reasoning ability of the student for a given set of letter and number sequences. The number and letter Series test questions demand both logic and mathematical knowledge. The questions are derived from fundamental basic concepts of number and letter patterns, formed based on functional relationships between them. There are various types of Number and Letter Series tricks and tips to solve Number and Letter Series questions for CAT.

The number and letter series comes in many exams such as CAT, GATE, ONGC, IBPS, SBI PO, and railways exams. It is also found in NDA, CDS, and central and state government job examinations.

Important Number and Letter Series Topics

Some of the important Number and Letter Series topics that are covered in the CAT questions are given below. 



Prime Number Series

Prime numbers are elements that have only two factors, i.e., the number itself and 1. The prime numbers start from 2, 3, 5, 7, 11, 13, 17. You can be asked questions based on these number patterns in different ways.

Difference Series

It contains the sequence in an order that is regulated by the differences in between the numbers.

Tips to Solve Number and Letter series Questions

  • Go through different number series like multiplication, division, squares, cubes, differences and more. These classifications can help you eliminate some of the available question options.
  • The letter series questions test your letter interpretation and reasoning skills. You should keep looking for any pattern that connects the letters in the given question.
  • Be familiar with the series’ concepts like letter positions, prime numbers, composite numbers, differences and more.
  • Read Number and Letter Series study guides to check various question patterns and their solution strategies.

Importance of Number and Letter series in CAT Exam

  • CAT exam focuses on the logical reasoning and problem-solving ability of the students. Hence Number and Letter Series is a hot topic for this exam.
  • Number and Letter Series questions and answers focus on the reasoning ability part of the assessment. They need the students to apply their interpretational and data analysing skills simultaneously to arrive at the answer.
  • This topic is also essential for other exams such as GATE and banking exams as well. The logical reasoning part of the CAT exam is necessary to pass and hence requires good preparation.

Most Recommended Books for Number and Letter Series 

Following books can be referred for CAT preparation in the given topic.

Book Title


Logical Reasoning- CAT

Arun Sharma

Logical Reasoning & Data Interpretation for the CAT

Nikhil K. Sinha

Why Prepare Number and Letter series from BYJU'S Exam Prep?

BYJU'S Exam Prep aims to provide you the best CAT exam preparation materials to get 100 percentile. You can get all the preparatory materials like Number and Letter Series questions and answers pdf, Number and Letter Series problems with solutions, Number and Letter Series questions and solutions from BYJU'S Exam Prep website. You must try your hand at solving many  Number and Letter Series practice questions before going for the CAT exam as it will help you in assessing your weak areas. To get familiar with the exam, you can take the Number and Letter Series quiz from our website. To prepare well for the exams, our experienced educators have prepared Number and Letter Series notes for students. It will help you to revise the Number and Letter Series topics in a short time.

Frequently Asked Questions

1. What is the Number and Letter Series definition?

There is no proper definition for the Number and Letter Series as it comprises a vast area of logical reasoning. Number series is a series formed by different patterns of number and similar is the letter series.

2. Do the Number and Letter Series come in CAT exams?

Yes, the number and Letter series helps in assessing the analytical and logical capabilities of the student. It is an integral part of the CAT syllabus.

3. How can I prepare for the Number and Letter Series?

There are many good ed-tech sites, including BYJU'S Exam Prep, where you can prepare for the topic. They provide definitions with number and letter series examples for better understanding. 

4. Is the number and letter series an easy topic to learn?

Number and Letter Series need a fair amount of mathematical and reasoning capabilities. It is a heavy CAT topic that comes in the exam. You can easily prepare for this topic from various online sites.

5. Why is the number series important in this exam?

Number series forms a good amount of questions as it takes numbers arranged in various patterns.