The ratio of the number of mystery books to the number of science fiction books is 4 : 3. The ratio of the number of science fiction books to the number of biographies is 4 : 5. If there are 48 science fiction books, find the total number of books.

                         4:3     Mystery Books:Science Fiction Books(48)                  48 divided by 3 = 16                  16 multiplied by 4= 64There are 64 Mystery Books.                          4:5 Science Books(48):Biographies                   48 divided by 4 = 12                   12 multiplied by 5 = 60The are 60 Biographies Mystery Books               64  Science Fiction books     48 Biographies                  +60                                     ------                                     172I hope that helped!