# Number Series IV - Number Series Questions for IBPS PO Exam

Read this post to discover the smart methods to solve number series questions in less time for IBPS PO Exam

Number series questions are an integral part of SSC IBPS PO Exams. These questions can’t be avoided by the aspirant because these questions are asked every year. Number series questions are the questions that check your analysing ability. IBPS PO Exam don't just check only your accuracy but also check your speed.

In our previous posts, we have discussed basics of number series and tips and tricks to solve number series questions. In this post, we will discuss few number series questions that are frequently asked in IBPS PO Exam
Example: Number Series Questions for IBPS PO Exam

Question: 1, 4, 27, 256, ?, 46656

Solution: The trick behind solving this number series question is that when we observe the series, we find that the series is increasing at a very high pace. The numbers are either multiples, squares or cubes of consecutive natural numbers.

As 1¹ = 1, 2² = 4, 3³ = 27, 4⁴ = 256, 5⁵ = 3125.
Therefore, the missing number is 3125.

Example: Number Series Questions for IBPS PO Exam

Question: 7, 26, 63, 126, 215, 342

Solution: In this number series question we need to find the wrong number which is placed in the series.

When we observe the series, we find that the numbers in the series are one less than the cube of the natural numbers starting from 2.
Therefore, The wrong number is 126.

Example: Number Series Questions for IBPS PO Exam
Question: 7, 11, 4, 18, 15, 5

Solution: The trick behind solving this number series question is that when we observe the series we find the number 7, 11, 4, 18, 14. They are in increasing and decreasing order. It's tough to analyse. But when we add 7 and 4 we get 11 and when we add 4 and 14 we get 18. This means that when we add alternate numbers, we get the middle number that is placed between them.
Therefore, The wrong number placed in the series is 15.

Example: Number Series Questions for IBPS PO Exam

Question: 12, 17, 24, 33, 52, ?

Solution:

When we observe the series, we find that the series is increasing gradually. So we can find the missing number by finding the difference between two numbers.
So when we subtract 17 - 12 = 5, 24 - 17 = 6, 33 - 24 = 10, 52 - 33 = 19.
As there is no specific pattern, we further find the difference of the differences.
6 - 5 =1, 10 - 6 = 4, 19 - 10 = 9, 35 - 19 = 16.

When we observe the difference, of the differences we find that these numbers are the squares of natural number starting from 1.

Therefore, the missing number is 87.

However, if you can't find the logic behind the series within 30 seconds, it's advisable to move on to another question and come back at the end when the time is left.

Number Series Questions for Practice

Question: What would come in place of question-mark (?) for the following question?

1 ? 9 16 25

1) 2            2) 5               3) 3              4) 4             5) None of these

Question: Find out the wrong number 60, 48, 38, 28, 24, 20, 18

1) 60       2) 48         3)38         4)28          5) 24