21, 9, 21, 11, 21, 13, 21, ... What number should come next?
A. 14
B. 15
C. 21
D. 23
Answer: Option B
Solution (By Examveda Team)
In this alternating repetition series, the random number 21 is interpolated every other number into an otherwise simple addition series that increases by 2, beginning with the number 9.This Question Belongs to Competitive Reasoning >> Number Series Completion
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