4 miles = 1 day
4miles divided by 1/3 distance on 2nd day = 1.33 miles ran on second day
4/1 x 1/3=4/3 4 divided by 3= 1.33 miles ran on the second day
If Will ran 1/3 of the distance that he ran on the first day (4 miles) the second day, he ran 1.33 miles