Sample Number Series Reasoning Questions

1. In the following question find the missing term: 3,8,5,27,8,64,12,125,17,? [SSC CGL Tier 1 2017]

a) 216

b) 361

c) 625

d) 441

Solution: If we check the series we can see that the difference between first, third, fifth, seventh, ninth term is increasing by 1. Lets see 5-3=2, 8-5=3, 12-8=4, and 17-12=5. Now to solve this type of problem you have to remember the square and cube of numbers.

If we check the series again we can see that there is 8 which is the cube of 2 (difference of third and first number), 27 which is the cube of 3 (difference of fifth and third number), similarly if we observe we can see that there is 64 which is the cube of 4 (difference of seventh and fifth number), 125 which is the cube of 5 (difference of ninth and seventh number), so the correct answer will be cube of 6 means 216 which is option a.

2. Which number will replace the question mark (?) in the following series? 1331, 2197, ?, 6859. [SSC CGL Tier 1 2022]

a) 4913

b) 5832

c) 4096

d) 3375

Solution: If we observe the series we can see that every number present in the series is a cube of a particular number. 1331 is the cube of 11, and 2197 is the cube of 13, also, 6859 is the cube of 19. So the correct option will be a perfect cube and also it would be the cube of the next prime number between 13 and 17. We know that 17 is the only prime number between 13 and 19. So the correct option will be cube of 17 means 4913 which is option a.

3. Find the next number in the series: 12, 7, 21, 16, 30, ?

a) 35

b) 40

c) 25

d) 45

Solution: The series follows the pattern of alternately subtracting 5 and adding 14:

12 – 5 = 7

7 + 14 = 21

21 – 5 = 16

16 + 14 = 30

So, the next number will be 30 – 5 = 25.
4. Find the next number in the series: 0, 1, 1, 2, 3, 5, ?

a) 6

b) 7

c) 8

d) 9

Solution: The series follows the pattern of adding the two previous numbers to get the next number:

0 + 1 = 1

1 + 1 = 2

1 + 2 = 3

2 + 3 = 5

So, the next number will be 3 + 5 = 8.

Number Series is a fundamental and frequently tested topic in competitive exams such as SSC (Staff Selection Commission) and bank recruitment examinations. It forms a crucial part of the quantitative aptitude or numerical ability section in these exams. A number series consists of a sequence of numbers arranged in a specific pattern or order, and the task is to identify and understand this pattern to predict the next number or missing number in the series.

Below are some practice Number Series Logical Reasoning Questions that can help applicants do well on such exams by giving them practice. The article also includes many approaches to answering a question on number series. Candidates are advised to review the questions to prepare for competitive examinations.