Question

How fast must I drive for the rest of the way to catch my train? I drive at an average speed of 30 miles per hour to the railroad station each morning and just catch my train. On a particular morning there was a lot of traffic and at the halfway point I found I had averaged only 15 miles per hour. How fast must I drive for the rest of the way to catch my train?

Answer 1

Theoretically it is impossible as all the time is already gone in covering half the distance at half speed.

Answer 2

your train is already gone.