In following number series, two terms have been put within brackets. Choose the appropriate option - Look at this series: 21, 9, 21, 11, 21, 13, . . .What number should come next?

C. 21

In following question, a number series is given with one term missing. Choose the correct alternative that will same pattern and fill in the blank spaces. - 20, 19, 17, x , 10, 5

C. 14

In following number series, two terms have been put within brackets. Choose the appropriate option - 2 , 5 , 9 , 19 , 37 , x

B. 75

In following number series, two terms have been put within brackets. Choose the appropriate option - Look at this series: 31, 29, 24, 22, 17, . . . What number should come next?

A. 15

In following questions, one term in number series is incorrect. - Find out the incorrect number 3, 5, 7, 9, 11, 13

D. 9