speed = [tex] \dfrac{\text{distance}}{\text{time}} [/tex]
speed = [tex] \dfrac{\text{1.5}}{\text{10 minutes}} [/tex]
speed = [tex] \dfrac{\text{1.5}}{\frac{10}{60}\text{hours}} [/tex]
speed = [tex]1.5 \times \frac{60}{10} [/tex]
speed = 9 miles/hour
The average speed is 9 miles/hour