Nancy is running 5.3 miles long after 20 minutes she has run 1.45 miles solve the equation to find the number of miles nancy has to run to get to the end of the trail

The question states that Nancy has to run a trail that is 5.3 miles long.
After 20 minutes she has run and covered 1.45 miles off the trail.
total trail - 5.3 miles long 
distance covered - 1.45 miles
Therefore the number of miles that nancy has to cover to get to the end of the trail -x 
x = 5.3 - 1.45 
   = 3.85 miles
therefore 3.85 miles left to run to get to the end of the trail

Using the rise/run rule. you would get 2/6.simp. 1/3