# Number Series Aptitude Q & A – Part 4

This is the Part 4 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.

31. 10 34 12 31 14 28 16
A. 25 18
B. 30 13
C. 19 26
D. 18 20
A. 25 18
Explanation:
Two patterns alternate here. The first pattern begins with 10 and adds 2 to each number to arrive at the next; the alternating pattern begins with 34 and subtracts 3 each time.

32. 11 14 14 17 17 20 20
A. 23 23
B. 23 26
C. 21 24
D. 24 24
A. 23 23
Explanation:
This is a simple addition series with repetition. It adds 3 to each number to arrive at the next, which is repeated before 3 is added again.

33. Look at this series: J14, L16, __, P20, R22, … What number should fill the blank?
A. S24
B. N18
C. M18
D. T24
B. N18
Explanation:
In this series, the letters progress by 2, and the numbers increase by 2.

34. Look at this series: 4, 7, 25, 10, __, 20, 16, 19, … What number should fill the blank?
A. 13
B. 15
C. 20
D. 28
A. 13
Explanation:
Two series alternate here, with every third number following a different pattern. In the main series, 3 is added to each number to arrive at the next. In the alternating series, 5 is subtracted from each number to arrive at the next.

35. 3 8 10 15 17 22 24
A. 26 28
B. 29 34
C. 29 31
D. 26 31
C. 29 31
Explanation:
This is an alternating addition series that adds 5, then 2, then 5, and so on.

36. 4 7 26 10 13 20 16
A. 14 4
B. 14 17
C. 18 14
D. 19 14
D. 19 14
Explanation:
Two patterns alternate here, with every third number following the alternate pattern. In the main series, beginning with 4, 3 is added to each number to arrive at the next. In the alternating series, beginning with 26, 6 is subtracted from each number to arrive at the next.

37. 3 8 13 18 23 28 33
A. 39 44
B. 38 44
C. 38 43
D. 37 42
C. 38 43
Explanation:
In this simple addition series, each number is 5 greater than the previous number.

38. 61 57 50 61 43 36 61
A. 29 61
B. 27 20
C. 31 61
D. 29 22
D. 29 22
Explanation:
This is an alternating repetition series, in which a random number, 61, is interpolated as every third number into an otherwise simple subtraction series. Starting with the second number, 57, each number (except 61) is 7 less than the previous number.

39. Look at this series: 8, 22, 8, 28, 8, … What number should come next?
A. 9
B. 29
C. 32
D. 34
D. 34
Explanation:
This is a simple addition series with a random number, 8, interpolated as every other number. In the series, 6 is added to each number except 8, to arrive at the next number.

40. Look at this series: 31, 29, 24, 22, 17, … What number should come next?
A. 15
B. 14
C. 13
D. 12
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