Number Series is an important topic in the Numerical Ability section of IBPS RRB Clerk exam. These questions are one of the easiest and most scoring in the exam. These questions test your ability to identify patterns and apply logic quickly. Whether you’re preparing for Prelims or Mains, number series questions can help you gain 5 marks in just a few minutes. With regular practice, you can solve them in under 30 seconds. In this blog, we’ll explain the most asked types of number series questions, give solved examples, and share tips to help you master this topic. You can also download a free PDF of sample number series questions in IBPS RRB Clerk exam for practice.
To help you prepare better, we’ve created a free PDF with the most frequently asked number series questions in IBPS RRB Clerk exams. It includes all types of number series asked in the exam, with answers and explanations. In this PDF, we have included the 15 questions asked in the previous year on this topic. You can use it for daily revision or mock test practice. Download it now and start solving!
Click Here to Download Sample Number Series Questions PDF!
Number series questions appear regularly in the Quant section of the IBPS RRB Clerk exam. In Prelims, you may get 5 questions from this topic, and in Mains, the level may be slightly higher. These questions are quick to solve and don’t require long calculations. If you understand the pattern, you can solve them in seconds. That’s why this topic is a favourite among students. It helps you save time and boost your score. Practicing number series daily improves your speed, accuracy, and confidence in the exam.
Let’s look at the most common types of number series questions you’ll see in the exam. Each type has a different logic, and once you understand the pattern, solving becomes easy.
These series follow a fixed addition or subtraction pattern.
Example:
2, 5, 8, 11, 14, ?
Logic: Add 3 each time.
Answer: 17
These are the simplest types. Just check the difference between numbers. If it’s constant, it’s an arithmetic series.
Here, each number is multiplied or divided by a fixed number.
Example:
2, 4, 8, 16, 32, ?
Logic: Multiply by 2
Answer: 64
These series grow fast. Look at how the numbers increase or decrease. If the change is big, try multiplication or division.
These series use a mix of operations like adding and multiplying.
Example:
2, 5, 10, 17, 26, ?
Logic: Add 3, 5, 7, 9…
Answer: 37
Here, the difference between numbers increases in a pattern. Check how the gap changes and apply the logic.
These series are based on squares or cubes of numbers.
Example:
1, 4, 9, 16, 25, ?
Logic: Squares of 1, 2, 3, 4, 5…
Answer: 36
If the numbers look familiar, try checking if they are squares or cubes. These are easy to spot with practice.
In these series, two patterns run in alternate positions.
Example:
2, 4, 6, 10, 12, 14, ?
Logic: Two series: Even numbers and +4 pattern
Answer: 18
Check if every second number follows a different rule. These are tricky but easy once you spot the pattern.
Here, one number in the series is wrong. You have to find it.
Example:
3, 6, 12, 24, 50, 96
Logic: Multiply by 2 → 3×2=6, 6×2=12, 12×2=24, 24×2=48 (not 50)
Answer: 50 is wrong
These questions test your observation. Look for the number that breaks the pattern. Solve more wrong number series questions. Know more about wrong number series from here!
Odd one out questions are a special type of number series where one number doesn’t follow the pattern.
Solved Example
Question:
3, 6, 12, 24, 50, 96
Step-by-Step Logic:
Answer: 50 is the odd one out.
This number breaks the pattern of multiplying by 2. So it’s the incorrect number in the series.
Below, we have provided 5 solved examples which is most relevant for your upcoming IBPS RRB Clerk exam. First, try to solve it yourself without lifting a pen or paper, then see the solution.
1. Series: 7, 14, 29, 58, 117, ?
Step-by-Step Logic:
Answer: 234
Tip: When numbers grow quickly but not exactly double, check for alternating “×2” and “×2 + 1” patterns.
2. Series: 3, 9, 21, 45, 93, ?
Step-by-Step Logic:
Answer: 189
Tip: If multiplication doesn’t fit, check the differences. Many advanced series use differences that grow in a pattern.
3. Series: 2, 6, 18, 54, 162, ?
Step-by-Step Logic:
Answer: 486
Tip: Multiplication-based series often appear in Prelims. In harder sets, they may combine multiplication with addition.
4. Series: 5, 12, 26, 54, 110, ?
Step-by-Step Logic:
Answer: 222
Tip: Always check if the differences themselves form a series (like doubling, squares, or multiples).
5. Series: 1, 4, 13, 40, 121, ?
Step-by-Step Logic:
Answer: 364
Check the difference between the missing and wrong number series.
| Feature | Missing Number Series | Wrong Number Series |
| Definition | A number is missing in the series; you need to find it. | One number is incorrect in the series; you need to spot it. |
| Objective | Identify the correct number that completes the pattern. | Identify the number that breaks the pattern. |
| Pattern | All numbers follow a logical pattern except the blank. | All numbers follow a pattern except the wrong one. |
| Question Format | Usually shown as: 2, 4, __, 8, 10 | Usually shown as: 2, 4, 9, 8, 10 |
| Approach | Find the logic and apply it to fill the blank. | Find the logic and check which number doesn’t fit. |
| Answer Type | A number that completes the series. | A number that should be removed or replaced. |
| Common in Exams | Frequently asked in Prelims and Mains. | Often seen in Mains or higher-level reasoning sets. |
| Difficulty Level | Usually easier and quicker to solve. | Slightly tricky; needs careful observation. |
Number series questions are a scoring opportunity in the IBPS RRB Clerk exam. They are short, logical, and easy to solve once you understand the common patterns like addition, multiplication, squares, and alternating sequences. With regular practice and smart observation, you can solve most of these questions in under 30 seconds. The more you solve, the faster and more confident you’ll become in the exam. Keep practicing and stay consistent!
Related Blogs:
| IBPS RRB Clerk Cut Off 2025 | IBPS RRB Clerk Syllabus 2025 |
| IBPS RRB Clerk Salary 2025 | IBPS RRB Clerk Previous Year Paper |
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Generally, 5 questions are asked in the Prelims exam.
Yes. These questions are asked in Mains exam too, with a slightly higher difficulty level.
Start by checking the difference between numbers. If the change is big, try multiplication. Look for patterns like squares, cubes, or alternating logic. With practice, you’ll spot the rule in seconds.
Yes! With regular practice and understanding of patterns, you can solve most number series questions in 20–30 seconds. Use a timer while practicing to improve speed.
Disclaimer: This article has been prepared for informational and educational purposes only, based on previous exam trends, expert analysis, and publicly available data. It is not an official notification, and the Institute of Banking Personnel Selection (IBPS) — the official conducting authority for the RRB Clerk exam — has not endorsed or released the content herein. While every effort has been made to ensure accuracy, exam patterns and question types may change, and readers are advised to verify details with official IBPS updates. The practice material and predictions provided are intended to support preparation and should not be considered guaranteed exam content. Neither the authors nor PracticeMock accept responsibility for any discrepancies, errors, or outcomes arising from reliance on this article. For official information, please refer to the IBPS website.
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