Galvin bought 3/5 as many non-fiction books as fiction books from a book fair. He read 6 non-fiction books and 13 fiction books. He then had 3/4 as many non-fiction books left read as fiction books. How many books did Galvin buy altogether?
Lets say Galvin has x books left to read for fiction books. (X + 13) + (3x/4 + 6) = all books bought
(x+13)=5(3x/4 + 6)/3