Train A and Train B are traveling towards each other but are 2,100 miles apart. Train A is traveling at 50 mph and Train B is traveling at 35 mph. When will they collide?

Answer 1

The relative velocity is 85mph, and the distance is 2100 miles

In reality, the trains will have to stop for fuel and maintenance.

distance=rate*time
solve for time.

Answer 2

24.7 hours