There are 11 books on a shelf. 4 of these books are new. The rest of them are used. (a) What is the ratio of new books to used books?
(b) What is the ratio of all books on the shelf to used books?

The width of a rectangle is 20 units. can the perimeter p of the rectangle be 64 units when its length x is 11 units? no, because p = 2x + 2(20) no, because p ≠ 2x + 2(20) yes, because p ≠ 2x + 2(20) yes, because p = 2x + 2(20)