Respuesta :
Answer:
3 bookshelves.
Step-by-step explanation:
That would be 3 maths books and 3 reading books on 3 shelves.
He would need 3 book shelves. They both have a common multiple of 3. 6/3 = 2 so there will be 2 reading books per shelf. 9/3 = 3 so there will be 3 math books per shelf