1.  2, 3, 4, 4, 6, 8, 9, 12, 16
A. 3
B. 6
C. 9
D. 12

Answer: Option C

Explanation:

Pattern is : the series is the combination of three series -each term is twice the preceding term.
(i) 1st, 4st, 7st term i. e 2,4,9,.......
(ii) 2st, 5st, 8st term i, e 3,6,12.....
(iii) 3st, 6st, 9st 4,8,16......
So, 9 is wrong.