You start by figuring out how fast a lap is so you do
4.5 (4 1/2 miles)/3
=1.5 minutes
Which means it takes her 1.5 minutes to do 1/4 mile so you times that by four to get how long it takes her to run a mile
4x1.5
=6
This means it takes her 6 minutes to run a mile
To get this into miles per hour you divide 60 (because there’s 60 minutes in an hour) by 6 (her mile time)
60/6
=10
Therefore she is running 10 miles per hour
