3, 7, 6, 5, 9, 3, 12, 1, 15, (….)

Question:
3, 7, 6, 5, 9, 3, 12, 1, 15, (….)

[A].

18

[B].

13

[C].

-1

[D].

3

Answer: Option C

Explanation:

There are two series, beginning respectively with 3 and 7. In one 3 is added and in another 2 is subtracted.

The next number is 1 – 2 = -1.