So if Bill runs 10 miles in those 4 days then we need to find out Val's.
2 and 3/5. Well, we already know 2*4=8
so 0.6 (which is 3/5) multiplied by 4 is 2.4.
8+2.4=10.4
So here are the results for the distance covered in 4 days :
Val = 10.4 miles
Bill = 10 miles
Therefore, I think Val covers the most distance in 4 days.
Hope I helped :)