it is given that Tim can read 15 pages in 10 min.
so
page P will be proportional to time T
[tex]P\alpha\text{ T}[/tex][tex]P=KT[/tex]here K is the proportionality constant
[tex]\begin{gathered} K=\frac{P}{T} \\ K=\frac{15}{10}=1.5 \end{gathered}[/tex]so the answer is K = 1.5