Logical thinking based on numbers

1. Look at this series: 9, 9, 7, 7, 5, 5, ... What number should come next?
a. 1,1

b. 1,4

c. 2,2

d. 3,3
2. Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?
a. 14

b. 15

c. 16

d. 17

3. Look at this series: 8, 2, 8, 4, 8, 6, 8, ... What number should come next?
a. 10

b. 8

c. 6

d. 4
4. Look at this series: 2, 4, 6, 8, 10, ... What number should come next?
a. 16

b. 12

c. 18

d. 20
5. Look at this series: 201, 202, 203, 204, ... What number should come next?
a. 207

b. 206

c. 205

d. 209
6. Look at this alphabets: K, N, Q, ... What alphabet should come next?
a. 2017

b.  2014

c. 2012

d. 2018

7. Look at this series: 2, 6, 18, ... What number should come next?
a. 54

b. 24

c. 36

d. 42
8. Look at this series: 200,150, 100, ... What number should come next?
a. 175

b. 50

c. 75

d. 25
9. Look at this series: 100,75, 50, ... What number should come next?
a. 35

b. 45

c. 23

d. 25
10. Look at this series: 90, 80, 70, ... What number should come next?
a. 100

b. 60

c. 40

d. 20