Answer:
3/8
Explanation:
Let's use a sample number of 100 miles
If 3/8 was traveled the first day, then 37.5m were traveled on the first day.
Now on Sunday, there are 62.5m remaining in the trip. They travel 3/5 of that, meaning they went 62.5 * 3/5m. This turns out to be 37.5 miles that were traveled on Sunday.
37.5/100 = 3.8