Respuesta :

ankeet

Answer:

400 mph

Step-by-step explanation:

speed = distance / time

3600 miles /9 hours is 400 miles per hour.

400 mph
Explanation:
In 9 hours Catherine was traveling 3,600 miles in order to find the constant of how many mph the plane was traveling you would have to take the miles (3,600) divide it by the hours (9)