Fuse Puzzle - Page 2
In order to time 45 minutes, you need simultaneously to light both ends of the first fuse, and light one end of the second fuse.
After 30 minutes, the two burning ends of fuse one will meet, and fuse two will have 30 minutes of burning time left.
Light the remaining end of fuse two. 15 minutes later, the two burning ends of fuse two will meet.
You have timed 45 minutes!
Photo courtesy of lant_70 on flickr.