Mrs. Thompson and Mr. Jackson are taking an inventory of the textbooks in each of their rooms. Mrs. Thompson has 12 full boxes of books and 3 extra books
she keeps in case students forget their books for class. Mr. Jackson has 10 full
boxes of books with 6 extra books. While they were working on his inventory,
he remembered that he had 1 more box of books in his storage closet. When
they finished counting books, they discovered that each of them had the same
number of textbooks. If each box has the same number of books, how many
books are in each box?
4