# Number Series Aptitude Q & A – Part 2

This is the Part 2 Aptitude Questions and Answers section on Number series with explanation for various interview, competitive examination and entrance test. Solved examples with detailed answer description, explanation are given and it would be easy to understand.

11. Look at this series: 7, 10, 8, 11, 9, 12, … What number should come next?
A. 7
B. 10
C. 12
D. 13
B. 10
Explanation:
This is a simple alternating addition and subtraction series. In the first pattern, 3 is added; in the second, 2 is subtracted.

12. Look at this series: 36, 34, 30, 28, 24, … What number should come next?
A. 20
B. 22
C. 23
D. 26
B. 22
Explanation:
This is an alternating number subtraction series. First, 2 is subtracted, then 4, then 2, and so on.

13. Look at this series: 0.15, 0.3, ____, 1.2, 2.4, … What number should fill the blank?
A. 4.8
B. 0.006
C. 0.6
D. 0.9
C. 0.6
Explanation:
This is a simple multiplication series. Each number is 2 times greater than the previous number.

14. Look at this series: U32, V29, __, X23, Y20, … What number should fill the blank?
A. W26
B. W17
C. Z17
D. Z26
A. W26
Explanation:
In this series, the letters progress by 1; the numbers decrease by 3.

15. 17 32 19 29 21 26 23
A. 25 25
B. 20 22
C. 23 25
D. 25 22
C. 23 25
Explanation:
Here, there are two alternating patterns. The first begins with 17 and adds 2; the second begins with 32 and subtracts 3.

16. 17 14 14 11 11 8 8
A. 8 5
B. 5 2
C. 8 2
D. 5 5
D. 5 5
Explanation:
In this simple subtraction with repetition series, each number is repeated, then 3 is subtracted to give the next number, which is then repeated, and so on.

17. 8 12 9 13 10 14 11
A. 14 11
B. 15 12
C. 8 15
D. 15 19
B. 15 12
Explanation:
This is an alternating addition and subtraction series, in which the addition of 4 is alternated with the subtraction of 3.

18. 36 31 29 24 22 17 15
A. 13 11
B. 10 5
C. 13 8
D. 10 8
D. 10 8
Explanation:
This is an alternating subtraction series, which subtracts 5, then 2, then 5, and so on.

19. 6 20 8 14 10 8 12
A. 14 10
B. 2 18
C. 4 12
D. 2 14
D. 2 14
Explanation:
This is an alternating addition and subtraction series. In the first pattern, 2 is added to each number to arrive at the next; in the alternate pattern, 6 is subtracted from each number to arrive at the next.

20. 21 25 18 29 33 18
A. 43 18
B. 41 44
C. 37 18
D. 37 41
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