What is the next number in the series 4 12 6 9 8 6

The next number in the series will be:

                            10

We are given a series by:

            4     12     6     9     8     6

By looking at the series we observe that the series is operated by two operations alternatively.

The odd term of the series i.e. 1st term, 3rd term , 5th term and so on are obtained by adding 2 to each of the preceding term .

and the even term of the series i.e. 2nd term, 4th term, 6th term , 8th term and so on are obtained by subtracting 3 to each of the preceding term.

i.e.  odd series is:

4+2=6

6+2=8

8+2=10

even term of the series:

12-3=9

9-3=6

                 Hence, the answer is:  10