A runner is jogging at a steady vr =

3:8 km=hr. When the runner is L = 5:1 km

from the finish line, a bird begins flying

from the runner to the finish line at vb =

11:4 km=hr (3 times as fast as the runner).

When the bird reaches the finish line, it turns

around and flies back to the runner. Even

though the bird is a dodo, we will assume

that it occupies only one point in space, i.e., a

zero length bird.

How far does the bird travel? Answer in

units of km.

I'm way lost here. So far, I figure when the bird reaches the finish line, the bird will have traveled 5.1km while the human will have traveled 1.7km, leaving him 3.4km from the finish. I don't know where to go from here though, it seems like guess and check is the only way but I know that's not it

*edit* Ehh should've put this in high school math, my bad :\