Hi Makenzie,
Using the relationships stated T=kL/p (directly as L and inversely as p) where k is a constant that needs to be determined. You were told that T=5 hrs and L=100yds and p=10 workers so k=(5)*(10)/(100)=.5 worker-hrs/yd
So the relationship is T=.5L/p
Hope this helps
Regards
Jim