Answer :
Art books: 3 boxes x 15 art books = 45 art books
Math books: 2 bags x 11 math books= 22 math books
Total books: 45+22=67
67-30 =37 books remaining
Math books: 2 bags x 11 math books= 22 math books
Total books: 45+22=67
67-30 =37 books remaining