Answer:
[tex]\frac{1}{6}[/tex]
Step-by-step explanation:
If there are 12 pages in a book, then there are 12 possible outcomes when one opens up a book. There are only two possibilities when a person opens up either 9 or 11. Probability is;
[tex]\frac{wanted-outcomes}{total-outcomes}[/tex]
Wanted-comes = 2
total-outcomes = 12
[tex]\frac{2}{12}\\\\=\frac{1}{6}[/tex]
