Trains travel from one town to another town all day, always on the same track, always going nonstop and at the same speed. The noon train took 80 minutes to complete the trip, but the 4 PM train took an hour and 20 minutes. Why?
This was Gollum's final riddle from The Hobbit:
"This thing all things devours;
Bird, beasts, trees, flowers;
Gnaws iron, bites steel;
Grinds hard stones to meal;
Slay king, ruins town,
and beats a mountain down."
I am small, but, when entire, of force to set a town on fire!
Let but one letter disappear, I then can hold a herd of deer;
Take one more off, and then you'll find, I once contained all human kind.