The bridge story

Post date: Aug 13, 2014 8:38:7 PM

Logic will get you from A to B. Imagination will take you everywhere.

-- Albert Einstein

My soul mate has a wonderful mind. One of the coolest problems she taught me is the bridge construction problem. The problem statement is as follows.

"There is a river that is 10 meters wide. A user from point A on one side of the river wants to get to point B on the other side of the river which is 20 meters away from the projection of A on the river side of point B. How should the bridge be constructed so that the user can go from A to B with the minimum amount of time?"

Please take your time to think through this carefully before reading on for the answer.

Ok. Here's the answer, and I hope it is just as mind-opening for you as it was for me: You build a bridge that is 20 meters wide, so that A can get straight to B! The moral here is that if you are stuck with an image of a narrow bridge in your head, then it's hard come up with a reasonable answer. However, if you let your brain to be wide-open, just like the bridge in the answer, then a solution is obvious.