**The simpler solution: **

**Step 0:** Ignore the fly!

**Step 1:** The two trains are moving together at a speed of s_{L} + s_{R}, and so it will take d_{0} / (s_{L} + s_{R}) hours to meet.

**Step 2:** In that time the fly will have traveled s_{F} x d_{0} / (s_{L} + s_{R})

**In the particular case: **The engines are 60 miles apart, approaching each other at 60 mph (each is traveling at 30 mph), so they will meet in 1 hour. In that time the fly will have flown 60 miles!

Last updated 2002/05/30

© J.A.N. Lee, 2002.