George has a total of B books in his library, 25 of which are hardcover fiction books. What is the value of B ?
(1) 40 of the B books are fiction and the rest are nonfiction.
(2) 60 of the B books are hardcovers and the rest are paperbacks.
1+2 fiction nonfiction total hardcover 25 35 60 paperback 15 ? B-60 Total 40 B-40 B 还是不知道paperback nonfiction, E.