Look at this series: 22, 21, 23, 22, 24, 23, . . . What number should come next? - Number Series - S

In following number series, two terms have been put within brackets. Choose the appropriate option - Look at this series: 22, 21, 23, 22, 24, 23, . . . What number should come next?

A. 22

B. 24

C. 25

D. 26

E. None of the above

Answer: C. 25

In this simple alternating subtraction and addition series;
1 is subtracted, then 2 is added, and so on.
Rule = (first number - 1) (second number + 2) (third number - 1) (fourth number + 2)......
Now The series is 22, 21, 23, 22, 24, 23, . . .
(22 - 1 = 21), (21 + 2 = 23), (23 - 1 = 22), (22 + 2 = 24), (24 - 1 = 23) (23 + 2 = 25)...
So the answer is c = 25.

Posted in: Number Series - Series Completion - Verbal Reasoning