The answer is: 12.
http://wiki.answers.com/Q/What_is_the_next_number_...

The next number in the series 38 36 30 28 22 is 20. Is there
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20
http://www.blurtit.com/q862692.html

22. This is an alternating number subtraction series. First, 2 is subtracted, then 4, then 2, and so on.
http://qna.rediff.com/questionsandanswers/looka...
