As the IBPS PO exam approaches soon, candidates have started to focus on the most scoring and time-efficient topics, such as wrong number series. If you just get the pattern, you will be easily able to get the answer, and that too in less than 5 minutes. This type of question is asked in the examination to test your logical ability, pattern recognition, and mental calculation skills.
What is a Wrong Number Series?
In a wrong number series question, you are presented with a number series that has a logical pattern, out of which one number or set is not following or fitting in the pattern. Your task is to find out the number, as it will be considered the wrong number.
Example:
Common Patterns in Wrong Number Series
There are approximately eight different types of wrong number series, out of which questions can be asked, and they are mentioned in the table below-
| Pattern Type | Explanation | Example |
| Addition/Subtraction | Each term is formed by adding/subtracting a number | 5, 10, 15, 25, 35 → wrong: 25 |
| Multiplication/Division | Numbers multiplied/divided by fixed or varying factors | 2, 4, 8, 16, 33, 64 → wrong: 33 |
| Squares & Cubes | Use of perfect squares/cubes in a sequence | 1, 4, 9, 16, 25, 36, 50 → wrong: 50 |
| Prime Numbers | Series formed with primes or manipulation of primes | 2, 3, 5, 7, 11, 13, 17, 20 → wrong: 20 |
| Fibonacci Series | Each term is the sum of the previous two numbers | 1, 1, 2, 3, 5, 8, 14 → wrong: 14 |
| Alternate Pattern | Every second term follows a different rule | 2, 4, 6, 10, 14, 22 → wrong: 22 |
| Difference Pattern | Look at the pattern in the differences between terms | 4, 7, 11, 16, 22, 29, 37 → wrong: 37 |
| Mixed Operations | A mix of addition, subtraction, multiplication, division, or squares in alternating or irregular order | 3, 6, 18, 72, 360, 2160, 15120 → wrong: no wrong number |
Study Resources Based On the Latest Pattern
How to Approach Wrong Number Series in the IBPS PO 2025 Exam
In such tricky and pattern recognition-type questions, candidates require a specific way to approach such questions, and here is a step-by-step procedure to do the same.
Check the Differences
Start with first-order differences, meaning that the pattern is consecutive or alternating. If not, then look for a multiplication pattern. Here is an example to explain the same.
Example
1, 3, 7, 13, 21, 31 → Difference: +2, +4, +6, +8, +10
So next should be 43, not 31. Hence, 31 is incorrect.
Try Multiplication or Division
If the first step of addition and subtraction doesn’t work, then check if the numbers are multiplying or dividing by a certain factor or not.
Example: 2, 6, 18, 54, 216, 648 → The correct pattern is ×3
If any number breaks this, it’s likely wrong.
Spot Squares or Cubes
If the above pattern is not applicable, then go for perfect squares/cubes or combinations of them.
Example:
4, 9, 16, 25, 36, 49, 60 → 60 is not a square. So it’s the wrong one.
Consider Alternating Patterns
If squares and cubes are not there in the pattern, then look for altered patterns such as –
Example:
10, 20, 15, 30, 20, 40 → Alternating +10 and +5. So, 20 (in position 5) breaks the pattern.
Use Approximation for Complex Series
If the question contains complex series, then go for the approximation method, where you just guess, but only if you are short on time; otherwise, try to mix and match the above-explained methods.
Time-Saving Tips for IBPS PO Prelims
As there is a sectional time limit in IBPS PO Prelims Examination, it is necessary to manage time as a wrong number series is time-consuming if you are not getting the pattern.
- Attempt only those questions where you recognize the pattern within 30 seconds.
- Practice at least 10 questions daily to get pro at recognizing patterns.
- Give a sectional topic test, as this will help you to become exam-ready.
Practice Question PDF for IBPS PO Wrong Answer Series
If you practice questions, then only you will get an idea of the exam and its difficulty level. To help you in this, we have curated a PDF that contains questions for practicing the wrong answer series for IBPS PO Exam. The link is given below-
Conclusion
In this blog, we have discussed in detail the pattern of questions asked in wrong number series, along with the step-by-step procedure to solve them. To get yourself exam-ready, you can take our mock test series, which are designed to make you a pro in such tricky and advanced topics. The link is given below.
FAQs
Firstly, observe the pattern, then try to apply that pattern throughout the series. If any number does not follow the pattern, then it will be considered a wrong number.
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