Greatest number of shelves is 4.
Number of adventure book on each shelf is 4.
Number of mysteries book on each shelf is 8.
Number of biographies book on each shelf is 3.
Explanation:
Here Sally has 16 adventure books, 32 mysteries, and 12 biographies.
The greatest number dividing all the numbers are 4.
So number of shelves is 4.
Greatest number of shelves is 4.
Number of adventure book on each shelf is 4.
Number of mysteries book on each shelf is 8.
Number of biographies book on each shelf is 3.