## Number Series Questions and Answers Part-8

1. 20, 20, 17, 17, 14, 14, 11, ... choose which pair of numbers comes next?
a) 8, 8
b) 11, 11
c) 11, 14
d) 11, 8

Explanation: This is a simple subtraction with repetition series. It begins with 20, which is repeated, then 3 is subtracted, resulting in 17, which is repeated, and so on.

2. 61, 57, 50, 61, 43, 36, 61, ... choose which pair of numbers comes next?
a) 29, 61
b) 27, 20
c) 31, 61
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.

3. 9, 12, 11, 14, 13, 16, 15, ... choose which pair of numbers comes next?
a) 14, 13
b) 18, 21
c) 14, 17
d) 18, 17

Explanation: This is a simple alternating addition and subtraction series. First, 3 is added, then 1 is subtracted, then 3 is added, 1 subtracted, and so on.

4. 4, 8, 22, 12, 16, 22, 20, 24, ... choose which pair of numbers comes next?
a) 28, 32
b) 28, 22
c) 22, 28
d) 32, 36

Explanation: This is an alternating repetition series, with a random number, 22, interpolated as every third number into an otherwise simple addition series. In the addition series, 4 is added to each number to arrive at the next number.

5. 40, 40, 31, 31, 22, 22, 13, ... choose which pair of numbers comes next?
a) 13, 4
b) 13, 5
c) 4, 13
d) 9, 4

Explanation: This is a subtraction series with repetition. Each number repeats itself and then decreases by 9.

6. What will come at the place of question mark ?
2, 3, 6, 15, ?, 123
a) 47
b) 42
c) 45
d) 50

Explanation:

First term → 2

Second term → (2 *3 -3) = 3

Third term → (3 *3 -3) = 6

Fourth term → (6 *3 - 3) = 15

Fifth term → (15 *3 - 3) = 42

Sixth term → (42 *3 - 3) = 123

7. In the following number series a wrong number is given. Find out the wrong number.

1, 3, 10, 21, 64, 129, 356, 777
a) 129
b) 21
c) 10
d) 356

Explanation:

The given pattern is,
2nd term → 1*2+1 = 3
3rd term → 3*3+1 = 10
4th term → 10*2+1 = 21
5th term → 21*3+1 = 64
6th term → 64*2+1 = 129
7th term → 129*3+1= 388
So, 7th term 356 is wrong and must be replaced by 388.

8. What will come at the place of question mark ?
9, 27, 31, 155, 161, 1127, ?
a) 316
b) 1135
c) 1288
d) 2254

Explanation:

Given pattern is,
2nd term → 9*3 = 27
3rd term → 27+4 = 31
4th term → 31*5 = 155
5th term → 155+6 = 161.
6th term → 161*7 = 1127
Missing term → 1127+8 = 1135.

9. What will come at the place of question mark ?
2, 7, 27, 107, 427, ?
a) 1262
b) 1707
c) 4027
d) 4207

Explanation:

The pattern is,
2nd term → 2 +(5 *12) = 7
3rd term → 7 +(5 *22) = 27
4th term → 27 +(5 *42) = 107
5th term → 107 +(5 *82) = 427
Missing term → 427 +(5 *162) = 1707

10. Sunday, Monday, Wednesday, Saturday, Wednesday, Monday, ...
a) Sunday, Sunday
b) Sunday, Monday
c) Sunday, Wednesday
d) Sunday, Saturday