Answer: 33
Artists : photographers = 3 : 2, and there are 9 artists, so there are 6 photographers. Then, the ratio of photographers to writers is 1 : 3, so there are 18 writers. Finally, there are half as many editors as writers, so there are 9 editors.
There are 6 + 18 + 9 = 33 photographers, writers and editors total.
i hope this helps! :D