Road trips can be fun, but they often appear to go slower the closer you get to your destination. I thought up this puzzle while on a recent trip. Thought it would be good food for thought. Curious about the different approaches to solving it.
Suppose you have D miles until you reach your destination. The rule is that the speed at which you travel is equal to the distance to your destination. So when you are 60 miles from your destination your speed must be 60 mph; 50 miles from destination, 50 mph; etc.
How long until you reach your destination?
EDIT:
I'm pretty sure that the answer is infinity—you will never get to your destination because you will always be one hour away. I'm curious about how people come up with their solutions. So far, very entertaining.
Best Answer
Your speed is strictly decreasing, so at any time, you know that it takes you at least one hour which would be the arrival time at present speed. So, you cannot reach the destination which is always more than an hour away.