To find the speed of each friend, we have to divide.
[tex]\begin{gathered} \text{Ethan}=\frac{50}{45}\approx1.11 \\ \text{Peter}=\frac{90}{75}=1.2 \\ \text{Harvey}=\frac{150}{120}=1.25 \\ \text{Alex}=\frac{80}{60}\approx1.33 \end{gathered}[/tex]Notice that we used 120 minutes instead of 2 hours, and 60 minutes instead of 1 hour because we had to have the same unit for time.
As you can observe in the calculations above, the fastest friend is Alex, he read 1.33 pages per minute.