Answer:
6 hours
Explanation:
Let's say that the number of hours that Yumi picked litter for is y.
You know that since Yumi picked litter for 2 hours more than Juan, y=x+2.
y=3m
x=2m
Subtract the second equation from the first:
y-x=m
Substitute:
x+2-x=m
2=m
This means that it takes 2 hours per mile of litter. Multiplying this by the 3 miles that Yumi walked makes a total of 6 hours. Hope this helps!