For the information given in the statement you have
[tex]8\text{ pages}\rightarrow15\text{ minutes}[/tex]Then
[tex]\begin{gathered} 16\text{ pages}\rightarrow30\text{ minutes} \\ 24\text{ pages}\rightarrow45\text{ minutes} \\ 32\text{ pages}\rightarrow60\text{ minutes} \\ \text{.} \\ \text{.} \\ \text{.} \end{gathered}[/tex]And so on.
Then, making the graph that represents this situation you have