There are 30 books in a bookcase. The books in the bookcase are all poetry, history, and art books. Ten of the books are art books. There are 6 fewer poetry books than history books. How many poetry books are in the bookcase?

If there is 30 per book shelf and they are saying it's 6 short then the answer is 24

Poetry + History + Art = 30 10 books for art Poetry is 6 fewer than history or h - 6 History is h Art is 10 All three = 30 So, h-6 + h + 10 = 30 2h + 4 = 30 2h = 26 H=13 Since poetry books are h - 6 There are 13-6 = 7 poetry books, 13 history, and 10 art