A squirrel ran 9 miles in 1 hour. Which expression can be used to determine its speed in miles per hour?9 miles : 1 hour1 hour : 9 miles1 mile : 9 hours9 hours : 1 mile

The correct answer is:

The expression 9 miles : 1 hour can be used to determine its speed

That is simply how we can calculate the speed if we divided distance by time e. g. in this case

If we divided 9 by 1 we will get 9, which will actually be the speed of the object.

Such simple calculations are used to determine everything from the estimated arrival time of a Train to the estimated arrival time of an International Flight.