Well let's see, one way to figure it out it by multiplying. So if she can walk 5 miles in 30 minutes and 1 hour is 60 minutes,
we would need to multiply 30 x 4, which is 120.
Now that we know 120 is 2 hours, and 4 times 30 minutes, we need to multiply 4 x 5, which is 20.
So now we know that, 5 miles = 30 minutes
and
20 miles = 120 minutes or 2 hours
hope this helps.
